Good evening,
I have been tasked with creating a dynamic Rhombus with a frame message inside.
I've been looking for a way to do this for a few hours now, but I'm honestly starting to lose my mind.
Note that my level is pretty basic, so my code doesn't include any complex materials.
I managed to create the upper half of the Rhombus, but I have no idea how to get the message exactly in the middle of it.
The user should be able to enter a string, a size and a character for the frame.
F.ex:
user input is:
5, $, Hello:
$
$ $
$ $
$ $
$ Hello $
$ $
$ $
$ $
$
My code so far (few unreferenced variables, ignore them):
void framedMessage()
{
int size = 6, i, sp, sym, a, b;
char rSymbol = '$', str[100] = { "Hello" };
//while ((strlen(str) % 2) == 0)
//{
// puts("Please Enter a string (even number of letters will be denied):");
// gets(str);
//}
//puts("Please enter a char for the rhombus(NOTE that the letters 'C','M','S','P','E' will return as small chars and not capital:");
//rSymbol = charInput();
//size = numericalInput(strlen(str) + 2, 999);
for (a = 0;a <= size;a++)
{
for (sp = 1;sp <= size;sp++)
{
if (sp == size && a == 0)
printf("%c", rSymbol);
if ((sp == size - a && a != 0))
{
printf("%c", rSymbol);
for (;sp < size + a;sp++)
{
printf(" ");
if (sp == size + a -2)
printf("%c", rSymbol);
}
}
printf(" ");
}
puts("");
}
}
The top half of the Rhombus wasn't so hard, but now I have no idea how to put the message in a way that will fit the space perfectly (have in mind that the string can't have an even amount of characters because it would ruin the rhombus).
I would appreciate any help with this. constructive posts about the code itself (what should I try to improve, avoid using etc..) would be greatly received.
Thanks a lot.
Since in this example you have used 6 as the size. The total no of spaces in next line between the two '$'s will be 11. ie double the value of variable size -1. So you get the length of the string and use the below logic to get the string in the middle.
len = strlen(str);
x = ( (size*2-1) - len)/2
in the case x will be 3
x No of spaces is required before and after str.
Related
I tried to use for loop calculate the number of books keyed in and sum up their total price, but at the end i only get zero price in C program. What is my problem ? How to solve it?
#include<stdio.h>
int main(void)
{
int booknum;
float bookfee,bookgst,nogst,totfee,newfee,newfee_nogst;
bookgst=0.0;
nogst=0.0;
int cnt;
char code;
printf("Key in total books purchased >> ");
scanf("%d",&booknum);
for(cnt=1;cnt<=booknum;cnt++)
{
printf("\n\n");
printf("Key in price of the book >> ");
scanf("%f",&bookfee);
printf("Key in type( S=standard gst,Z=zero gst) \n>> ");
scanf("%c",&code);
getchar();
if(code=='S')
{
newfee=bookfee+0.6;
}
else if(code=='Z')
{
newfee_nogst=bookfee;
}
bookgst=bookgst+newfee;
nogst=nogst+newfee_nogst;
printf("\n");
}
totfee=bookgst+nogst;
printf("Book purchased with GST : RM %.2f\n",bookgst);
printf("Book purchased without GST : RM %.2f\n",nogst);
printf("Total payment : RM %.2f\n",totfee);
return 0;
}
There are a few problems with this code, but you're almost there!
First code reading needs to eat the previous \n (see this), otherwise the code is neither Z not S (it's a newline), and that's why the fees are never added.
(Search also for "fgets vs scanf" to see how to use the safer fgets).
scanf(" %c",&code);
then these lines
bookgst=bookgst+newfee;
nogst=nogst+newfee_nogst;
add the newfee / newfee_nogst ; these variables are set to 0 before the loop, but at the next occurence, they're still set to the value of the previous occurrence, thus either set them to 0 at the beginning of the loop, or, add the value directly in the if (see below). And since we're here, print an error if the code is wrong (and maybe subtract one to cnt to do one more loop with a correct code, in this case).
Also, the GST calculation is probably wrong, 6% of x is 0.06 * x, and if you want GST added to the value that's x * 1.06
if(code=='S')
{
bookgst = bookgst + bookfee*1.06; // or bookgst += bookfee*1.06
}
else if(code=='Z')
{
nogst = nogst + bookfee; // or nogst += bookfee
}
else {
printf("Code not understood\n");
}
Roy wants to change his profile picture on Facebook. Now Facebook has some restriction over the dimension of picture that we can upload.
Minimum dimension of the picture can be L x L, where L is the length of the side of square.
Now Roy has N photos of various dimensions.
Dimension of a photo is denoted as W x H
where W - width of the photo and H - Height of the photo
When any photo is uploaded following events may occur:
If any of the width or height is less than L, user is prompted to upload another one. Print "UPLOAD ANOTHER" in this case.
If width and height are both large enough and
(a) if the photo is already square then it is accepted. Print "ACCEPTED" in this case.
(b) else user is prompted to crop it. Print "CROP IT" in this case.
Code:
#include <stdio.h>
#include <stdlib.h>
int main (void)
{
int len; /* len is the length of the side of square */
scanf("%d",&len);
int test;
scanf("%d",&test);
while(test--)
{
int w,h;
/* w - width of the photo and h- Height of the photo */
scanf("%d %d",&w,&h);
if(w==len && h==len)
{
printf("ACCEPTED\n");
}
else if(w>len || w==len && h>len || h==len)
{
printf("CROP IT\n");
}
else
{
printf("UPLOAD ANOTHER\n");/* print */
}
}
return 0;/* success */
}
If your problem is that you're seeing no output at all, it's likely because it's running in an IDE and the output window is closing before you can see it. Judicious use of a getchar() at the end of main() may be all you need to fix this, though I'd probably prefer to just run it from the command line.
In any case, since && has a higher precedence than ||, your second condition is effectively:
else if ((w > len) || (w == len && h > len) || (h == len))
which is clearly wrong since having a photo with width more than what was necessary would result in a request for cropping regardless of the other sub-conditions.
You would be better off following the textual specs more closely so that you can actually check it more easily. That would entail something like (with slightly simplified specs still meeting the original intent):
If any of the width or height is less than L, user is prompted to upload another one.
Otherwise both are large enough. If the photo is already square then it is accepted.
Otherwise user is prompted to crop it.
The code for that is a much simpler:
if ((w < len) || (h < len)) {
puts ("UPLOAD ANOTHER");
} else if (h == w) { // Both large enough otherwise previous
puts ("ACCEPTED"); // condition would have been true.
} else {
puts ("CROP IT");
}
Due to operator precedence,
else if(w>len || w==len && h>len || h==len)
is equivalent to:
else if(w>len || (w==len && h>len) || h==len)
What you need to use is:
else if( (w>len || w==len) && (h>len || h==len) && (w == h) )
You can simplify that to:
else if( w >= len && h >= len && w == h )
which can be further simplified to:
else if( w >= len && w == h )
It will show output but the program runs faster than you expect. It will close as soon as the output is displayed . It will not wait till you read it.
So use getch(); declared in conio.h to get a single key press as input after you have printed all the output (right before the return statement. It will make the program wait for the user to press a key before exiting.
here is the screenshot. it is running without error on me.
NOTE: This is not an answer. But this is just the only way to give picture example :) no need to up
Maybe you only need to put getchar(); at the end of the code before return to let the screen to pause for a while. it is just exiting very fast
I wrote a program that allows a user to find the number of instances of a word or collection of words in any text file. The user can enter something like this in the command line:
$ ./wordCount Mars TripToMars.txt
to search for the number of instances of the word "Mars" in the book Trip To Mars, or
$ ./wordCount -f collectionOfSearchWords.txt TripToMars.txt
to search for the number of instances of several words on individual lines in collectionOfSearchWords.txt.
To ensure that the program was correct, I used the grep commands:
$ grep -o 'Mars' TripToMars.txt | wc -w
and
$ grep -o -w 'Mars' TripToMars.txt | wc -w
The first command finds the number of instances of the word anywhere, which would include terms like "Marsa", "Marseen", "Marses", etc., while the second command finds only instances of "Mars" as a standalone word, which would include trailing punctuation such as "Mars.", "Mars!", "Mars?", etc.
Both grep commands return 49 as the number of instances of "Mars" in the book.
When I use the code in the while loop below (for simplicity, I'm only including the relevant code), the program returns 49. Awesome!
FILE *textToSearch;
char *readMode = "r";
int count;
char nextWord[100];
char d;
textToSearch = fopen(argVector[argCount-1], readMode);
if (textToSearch == NULL) {
fprintf(stderr, "Cannot open %s to be searched\n", argVector[argCount-1]);
return 1;
} else {
while (fscanf(textToSearch, "%*[^a-zA-Z]"), fscanf(textToSearch, "%80[a-zA-Z]", nextWord) > 0) {
// increment the counter if the word is a match
if (strcmp(nextWord, argVector[word]) == 0) {
count++;
}
}
}
But when I substitute this while loop for the previous one, the program returns 17.
while(1) {
d = fscanf(textToSearch, "%s", nextWord);
if (d == EOF) break;
// increment the counter if the word is a match
if (strcmp(nextWord, argVector[word]) == 0) {
count++;
}
}
So, what's the big difference between
while (fscanf(textToSearch, "%*[^a-zA-Z]"), fscanf(textToSearch, "%80[a-zA-Z]", nextWord) > 0) {}
and
while(1) {
d = fscanf(textToSearch, "%s", nextWord);
if (d == EOF) break;
}
?
EDIT:
I added this code:
if (strcmp(nextWordDict, nextWord) == 0 ||
strcmp(nextWordDict, strcat(nextWord, ".")) == 0 ||
strcmp(nextWordDict, strcat(nextWord, "?")) == 0 ||
strcmp(nextWordDict, strcat(nextWord, "!")) == 0 ||
strcmp(nextWordDict, strcat(nextWord, ",")) == 0) {
count++;
}
to the code producing 17 for Mars to try and account for cases with trailing punctuation, and there was no change. Still 17.
EDIT2:
As John Bollinger correctly points out below, this code does nothing because the string buffered into nextWord would already have the trailing punctuation, and the code would only be adding more. This is faulty thinking on my part.
You are incorrect when you say that the command ...
$ grep -o -w 'Mars' TripToMars.txt | wc -w
... "finds only instances of 'Mars' as a standalone word", or at least that statement is misleading in context. The command finds instances of "Mars" that are not part of a larger word, where a "word" is defined as a contiguous string of letters, digits, and/or underscores. In particular, it will match "Mars" where it is followed by a punctuation mark, which conflicts with what you seem to be claiming.
But what is the difference between your two scanning approaches? Well, this ...
while (fscanf(textToSearch, "%*[^a-zA-Z]"),
fscanf(textToSearch, "%80[a-zA-Z]", nextWord) > 0) { /* ... */ }
... scans zero or more characters that are not Latin letters, ignoring whether any are matched and whether any input error occurs, then scans a contiguous sequence of up to 80 Latin letters, recording that sequence in the nextWord buffer.
On the other hand, this ...
while(1) {
d = fscanf(textToSearch, "%s", nextWord);
if (d == EOF) break;
}
... ignores leading whitespace, then scans the next contiguous string of non-whitespace into nextWord.
The two differ significantly in what they do with characters that are neither Latin letters nor whitespace: the former ignores them, whereas the latter includes them in nextWord. When you then compare nextWord with the string "Mars", the latter misses on
Going to Mars.
and
The name "Mars"
and
Is there water on Mars?
because the adjacent punctuation is included in the comparison. Your text is quite likely to have many constructions similar to those, and your grep commands do not demonstrate otherwise.
I have the raw and unfiltered records in a csv file (more than 1000000 records), and I am suppose to filter out those records from a list of files (each weighing more than 282MB; approx. more than 2000000 records). I tried using strstr in C. This is my code:
while (!feof(rawfh)) //loop to read records from raw file
{
j=0; //counter
while( (c = fgetc(rawfh))!='\n' && !feof(rawfh)) //read a line from raw file
{
line[j] = c; line[j+1] = '\0'; j++;
}
//function to extract the element in the specified column, in the CSV
extractcol(line, relcolraw, entry);
printf("\nWorking on : %s", entry);
found=0;
//read a set of 4000 bytes; this is the target file
while( fgets(buffer, 4000, dncfh)!=NULL && !found )
{
if( strstr(buffer, entry) !=NULL) //compare it
found++;
}
rewind(dncfh); //put the file pointer back to the start
// if the record was not found in the target list, write it into another file
if(!found)
{
fprintf(out, "%s,\n", entry); printf(" *** written to filtered ***");
}
else
{
found=0; printf(" *** Found ***");
}
//I hope this is the right way to null out a string
entry[0] = '\0'; line[0] ='\0';
//just to display a # on the screen, to let the user know that the program
//is still alive and running.
rawreccntr++;
if(rawreccntr>=10)
{
printf("#"); rawreccntr=0;
}
}
This program takes approximately 7 to 10 seconds, on an average, to search one entry in the target file (282 MB). So, 10*1000000 = 10000000 seconds :( God knows how much is that going to take if I decide to search in 25 files.
I was thinking of writing a program, and not going to spoon fed solutions (grep, sed etc.). OH, sorry, but I am using Windows 8 (64 bit, 4 GB RAM, AMD processor Radeon 2 core - 1000Mhz). I used DevC++ (gcc) to compile this.
Please enlighten me with your ideas.
Thanks in advance, and sorry if I sound stupid.
Update by Ali, the key information extracted from a comment:
I have a raw CSV file with details for customer's phone number and address. I have the target file(s) in CSV format; the Do Not Call list. I am suppose to write a program to filter out phone number that are not present in the Do No Call List. The phone numbers (for both files) are in the 2nd column. I, however, don't know of any other method. I searched for Boyer-Moore algorithm, however, could not implement that in C. Any suggestions about how should I go about searching for records?
EDITED
I would recommend you have a try with the readymade tools in any Unix/Linux system, grep and awk. You'll probably find they are just as fast and much more easily maintained. I haven't seen your data format, but you say the phone numbers are in the second column, so you can get the phone numbers on their own like this:
awk '{print $2}' DontCallFile.csv
If your phone numbers are in double quotes, you can remove those like this:
awk '{print $2}' DontCallFile.csv | tr -d '"'
Then you can use fgrep with the -f option, to search whether strings listed in one file are present in a second file, like this:
fgrep -f file1.csv file2.csv
or you can invert the search and search for strings NOT present in another file, by adding the -v switch to fgrep.
So, your final command would probably end up like this:
fgrep -v -f <(awk '{print $2}' DontCallFile.csv | tr -d '"') file2.csv
That says... search, in file2.csv for all strings not present (-v option) in column 2 of file "DontCallFile.csv". If you want to understand the bit in <() it is called process substitution and it basically makes a pseudo-file out of the result of running the command inside the brackets. And we need a pseudo-file because fgrep -f expects a file.
ORIGINAL ANSWER
Why are you using fgetc() anyway. Surely you would use getline() like this:
while(getline(myfile,line ))
{
...
}
Are you really reading the whole "target" file from the start for every single line in your main file? That will kill you! And why are you doing it in chunks of 4,000 bytes? And what if one of your strings straddles the 4,000 bytes you compare it with - i.e. the first 8 bytes are in one 4k chunk and the last however many bytes are in the nect 4k chunk?
I think you will get better help on here if you take the time to explain properly what you are trying to do - and maybe do it with awk or grep (at least figuratively) so we can see what you are actually trying to achieve. Your decription doesn't mention the "target" file you use in the code, for example.
You can do this with awk, like this:
awk -F, '
FNR==NR {gsub(/"/,"",$2);dcn[$2]++;next}
{gsub(/ /,"",$2);if(!dcn[$2])print}
' DontCallFile.csv x.csv
That says... the field separator is a comma (-F,). Now read the first file (DontCallFile.csv) and process according to the part in curly braces after FNR==NR. Remove the double quotes from around the phone number in field 2, using gsub (global substitution). Then increment the element in the associative array (i.e. hash) as indexed by unquoted field 2 and then move to next record. So basically, after file "DontCallFile.csv" is processed, the array dcn[] will hold a hash of all the numbers not to call (dcn=dontcallnumbers). Then, the code in the second set of curly braces is executed for each line of the second file ("x.csv"). That says... remove all spaces from around the phone number in field 2. Then, if that phone number is not present in the array dcn[] that we built earlier, print the line.
Here is one idea for improvement...
In the code below, what's the point in setting line[j+1] = '\0' at every iteration?
while( (c = fgetc(rawfh))!='\n' && !feof(rawfh))
{
line[j] = c; line[j+1] = '\0'; j++;
}
You might as well do it outside the loop:
while( (c = fgetc(rawfh))!='\n' && !feof(rawfh))
line[j++] = c;
line[j] = '\0';
My advice is the following.
Put all don't call phone numbers into an array.
Sort this array.
Use binary search to check if a given phone number is among the sorted
don't call numbers.
In the code below, I just hard-coded the numbers. In your application, you will have to replace that with the corresponding code.
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int compare(const void* a, const void* b) {
return (strcmp(*(char **)a, *(char **)b));
}
int binary_search(const char** first, const char** last, const char* val) {
ptrdiff_t len = last - first;
while (len > 0) {
ptrdiff_t half = len >> 1;
const char** middle = first;
middle += half;
if (compare(&*middle, &val)) {
first = middle;
++first;
len = len - half - 1;
}
else
len = half;
}
return first != last && !compare(&val,&*first);
}
int main(int argc, char** argv) {
size_t i;
/* Read _all_ of your don't call phone numbers into an array. */
/* For the sake of the example, I just hard-coded it. */
char* dont_call[] = { "908-444-555", "800-200-400", "987-654-321" };
/* in your program, change length to the number of dont_call numbers actually read. */
size_t length = sizeof dont_call / sizeof dont_call[0];
qsort(dont_call, length, sizeof(char *), compare);
printf("The don\'t call numbers sorted\n");
for (i=0; i<length; ++i)
printf("%lu %s\n", i, dont_call[i]);
/* For each phone number, check if it is in the sorted dont_call list. */
/* Use binary search to check it. */
char* numbers[] = { "999-000-111", "333-444-555", "987-654-321" };
size_t n = sizeof numbers / sizeof numbers[0];
printf("Now checking if we should call a given number\n");
for (i=0; i<n; ++i) {
int should_call = binary_search((const char **)dont_call, (const char **)dont_call+length, numbers[i]);
char* as_text = should_call ? "no" : "yes";
printf("Should we call %s? %s\n",numbers[i], as_text);
}
return 0;
}
This prints:
The don't call numbers sorted
0 800-200-400
1 908-444-555
2 987-654-321
Now checking if we should call a given number
Should we call 999-000-111? yes
Should we call 333-444-555? yes
Should we call 987-654-321? no
The code is definitely not perfect but it is sufficient to get you started.
The problem with your algorithm is complexity. You approach is O(n*m) where n is number of customers and m is number of do_not_call records (or size of file in your case). You need reduce this complexity. (And Boyer-Moore algorithm would not help there which suggested by Ali. It would not improve asymptotic complexity but only constant.) Even binary search as Ali suggest in his answer is not best. It would be O((n+m)*log m). We can do better. Nice solutions are using fgrep and awk as suggested by Mark Setchell in his answers. (I would chose one using fgrep which should perform better I guess but it is only guess.) I can provide one similar solution in Perl which will provide more robust CSV parsing and should handle your data sizes in easy on decent HW. This type of solutions has complexity O(n+m).
#!/usr/bin/env perl
use strict;
use warnings;
use autodie;
use Text::CSV_XS;
use constant PHN_COL_DNC => 1;
use constant PHN_COL_CUSTOMERS => 1;
die "Usage: $0 dnc_file [customers]" unless #ARGV>0;
my $dncfile = shift #ARGV;
my $csv = Text::CSV_XS->new({eol=>"\n", allow_whitespace=>1, binary=>1});
my %dnc;
open my $dnc, '<', $dncfile;
while(my $row = $csv->getline($dnc)){
$dnc{$row->[PHN_COL_DNC]} = undef;
}
close $dnc;
while(my $row = $csv->getline(*ARGV)){
$csv->print(*STDOUT, $row) unless exists $dnc{$row->[PHN_COL_CUSTOMERS]};
}
If it would not meet our performance expectation you can go down to C road but I would definitely recommend use some good csv parsing and hashmap libraries. I would try libcsv and khash.h
I am having a problem with a segmentation fault working in C, and I cannot figure out why this is occurring. I think it has something to do with misuse of the fget(c) function.
while((ch = fgetc(fp))!= EOF) {
printf("Got inside first while: character is currently %c \n",ch); //**********DELETE
while(ch != '\n') {
char word[16]; //Clear out word before beginning
i = i+1; //Keeps track of the current run thru of the loop so we know what input we're looking at.
while(ch != ' ') {
printf("%c ",ch); //**********DELETE
//The following block builds up a character array from the current "word" (separated by spaces) in the input file.
int len = strlen(word);
word[len] = ch;
word[len+1] = '\0';
printf("%s",word);
ch = fgetc(fp);
}
//The following if-else block sets the variables TextA, TextB, and TextC to the appropriate Supply Types from the input.
//This part may be confusing to read mentally, but not to trace. All it does is logically set TextA, B, and C to the 3 different possible values SupplyType.
if(word!=TextB && word!=TextC && i==1 && TextB!="") {
strcpy(TextA,word);
}
else if(word!=TextA && word!=TextC && i==1 && TextC!="") {
strcpy(TextB,word);
}
else if(word!=TextB && word!=TextA && i==1) {
strcpy(TextC,word);
}
switch(i) {
case 1:
if(TextA == word) {
SubTypeOption = 1;
}
else if(TextB == word) {
SubTypeOption = 2;
}
else if(TextC == word) {
SubTypeOption = 3;
}
break;
case 2:
//We actually ultimately don't need to keep track of the product's name, so we do nothing for case i=2. Included for readibility.
break;
case 3:
WholesalePrice = atof(word);
break;
case 4:
WholesaleAmount = atoi(word);
break;
case 5:
RetailPrice = atof(word);
break;
case 6:
RetailAmount = atoi(word);
break;
}//End switch(i)
ch = fgetc(fp);
}//End while(ch != '\n')
//The following if-else block "tallys up" the total amounts of SubTypes bought and sold by the owner.
if(SubTypeOption == 1) {
SubType1OwnersCost = SubType1OwnersCost + (WholesalePrice*(float)WholesaleAmount);
SubType1ConsumersCost = SubType1ConsumersCost + (RetailPrice *(float)RetailAmount);
}
else if(SubTypeOption == 2) {
SubType2OwnersCost = SubType2OwnersCost + (WholesalePrice*(float)WholesaleAmount);
SubType2ConsumersCost = SubType2ConsumersCost + (RetailPrice *(float)RetailAmount);
}
else if(SubTypeOption == 3) {
SubType3OwnersCost = SubType3OwnersCost + (WholesalePrice*(float)WholesaleAmount);
SubType3ConsumersCost = SubType3ConsumersCost + (RetailPrice *(float)RetailAmount);
}
}//End while((ch = fgetc(fp))!= EOF)
Using gdb (just a simple run of the a.out) I found that the problem is related to getc, but it does not tell which line/which one. However, my program does output "Got in side the first while: character is currently S". This S is the first letter in my input file, so I know it is working somewhat how it should, but then causes a seg fault.
Does anyone have any advice on what could be going wrong, or how to debug this problem? I am relatively new to C and confused mostly on syntax. I have a feeling I've done some small syntactical thing wrong.
By the way, this snippet of the code is meant to get a word from a string. Example:
Help me with this program please
should give word equaling "Help"
Update: Now guys I am getting kind of a cool error (although cryptic). When I recompiled I got something like this:
word is now w S
word is now w Su
word is now w Sup
... etc except it goes on for a while, building a pyramid of word.
with my input file having only the string "SupplyTypeA 1.23 1 1.65 1" in it.
UPDATE: Segmentation fault was fixed (the issue was, I was going past the end of the file using fgetc() ). Thanks everyone.
If anyone still glances at this, could they help me figure out why my output file does not contain any of the correct numbers it should? I think I am probably misusing atof and atoi on the words I'm getting.
Make sure you compile the program with -g -O0 options
Next step through the program line by line in GDB, watch and understand what your program is doing. Look at the various variables. This is the essential debugging skill.
WHen it dies type the command 'k' this will give you a stack trace the last line of the trace will have the failing line number, but you know that anyway because you were on the line shen you did a step command
There is no "fget" in good old C, but maybe you're using a more modern version that has something named "fget". Most likely, you meant to use "fgetc". When a C I/O function starts with "f", it usually wants a FILE* handle as an argument, as "fgetc" does. Try using "fgetc" instead, after reading the documentation for it.