#include<stdio.h>
int main() {
char text[1000];
int ch;
int index = 0;
while ((ch = getchar()) != EOF) {
text[index] = ch;
index++;
}
text[index] = '\0';
int i =0;
int num_Count=0;
int lower_Count=0;
int upper_Count =0;
while(i < index) {
if((text[i]>='0') && (text[i]<='9')){
num_Count ++;
i++;
}
else if((text[i]>='A') && (text[i]<='Z')){
upper_Count++;
i++;
}
else if((text[i]>='a') && (text[i] <='z')){
lower_Count++;
i++;
}
else
i++;
}
printf("%d %d %d", num_Count, lower_Count, upper_Count);
return 0;
}
It is a program that outputs the number of lower case, upper case, and number when the sentence is inputted.
For example,
Hi
Name
100
Would output 3 4 2
I keep seeing a runtime error.
The (while) part seems to be wrong.. I do not know what's wrong.
I ran your code in my system and checked for the input: Hi Name 100. The output I got is 3 4 2 which is the expected output. I feel the only place where the code can run in an infinite loop is while reading the inputs. Try to use ctrl+ d for EOF or ctrl+ z for windows.
Rest every thing is fine.
EOF means End Of File. It is used when you read data from a file. I suggest put a character like newline ('\n').
Related
In the following code example from K&R's book, if I replace putchar(c) with printf("%c", c) the code works the same. But if I replace it with printf("%d", c) it gives gibberish output.
#include <stdio.h>
int main() {
int c;
c = getchar();
while (c != EOF) {
putchar(c);
c = getchar();
}
}
From here, I learned that the getchar() converts the stdin to an 8-bit character whose value ranges from 0 to 255.
Now I want to print the value of c using putchar(c) in one line and printf("%d", c) in another line. So I wrote the following code:
#include <stdio.h>
int main() {
int c, b;
c = getchar();
b = c;
while (c != EOF && c != 10) {
printf("%c",c);
c = getchar();
}
printf("\n");
while (b != EOF && b != 10) {
printf("%d\t",b);
b = getchar();
}
}
I used the condition c != 10 as the newline character is read as 10 by getchar(). I expected the code to work as
$ ./a.out
783
783
55 56 51
but the program terminates as
$ ./a.out
783
783
55
I understand that getchar() takes input from stdin and the variable b is not stdin. So how should I copy the variable c to b so that my program works as I expect it to?
The problem is that your code does not (and cannot, as it stands) 'remember' the inputs you gave in the first loop. So, after you have finished that loop, your second loop is wanting to read in the characters for b (after it has output the first value, which is remembered from the earlier b = c line).
So, after outputting 55 (the integer value of the character 7), it is waiting for further input.
Probably the easiest way to get the output that you're looking for is to have an array of input characters. Then, you can output the %c values as you read them (as before), then re-run the outputs using the %d format in a subsequent for loop.
Here is a demonstration that does what I think you're after:
#include <stdio.h>
#define MAXINS 20 // Set to the maximum number of input characters you want to allow
int main()
{
int c[MAXINS];
int i = 0, n = 0;
c[0] = getchar();
while (i < MAXINS && c[i] != EOF && c[i] != 10) {
printf("%c", c[i]);
c[++i] = getchar();
++n;
}
printf("\n");
for (i = 0; i < n; ++i) {
printf("%d\t", (int)(c[i]));
}
return 0;
}
Feel free to ask for further clarification and/or explanation.
EDIT: On the point in the your first paragraph, "But if I replace it with printf("%d", c) it gives gibberish output." Well, when I try the following code and give 783 and then hit return (which generates a newline) I get the expected 55565110 as the output:
int main()
{
int c;
c = getchar();
while (c != EOF) {
printf("%d", c);
c = getchar();
}
return 0;
}
This may look like gibberish, but it's just the same output as you 'expect' in your later code, but without the spaces and with the addition of the 10 for the newline.
You need to have every character stored, because once you read a char from stdin, it is not present in stdin anymore.
Since you want the newline character in the end as a part of the input, you should use fgets to take the input.
Say you are taking an input that could have a maximum of 100 characters.
#include <stdio.h>
int main(void) {
char c[100]; // A char array
fgets(c,100,stdin);
int x=0;
while (c[x] != 10 && c[x] != EOF)
printf("%c",c[x++]);
printf("\n");
x = 0;
while (c[x] != 10 && c[x] != EOF) // You can simply compare it with the newline character too.
printf("%d ",c[x++]);
printf("\n");
return 0;
}
There are many ways to do this. You can also read stdin character-by-character ans store it in an array. However, since you need to display the ASCII values of the characters in another line after displaying the characters themselves, you will have to store them in an array.
You are copying only the first input, to copy the whole string you need to store each input in a buffer and check if the string doesn't overflow that buffer on each iteration:
int main(void)
{
enum {size = 256};
char buffer[size];
size_t count = 0;
int c;
while ((c = getchar()) && (c != '\n') && (c != EOF))
{
printf("%c", c);
if (count < size)
{
buffer[count++] = (char)c;
}
}
printf("\n");
for (size_t iter = 0; iter < count; iter++)
{
printf("%d\t", buffer[iter]);
}
printf("\n");
}
If you don't want to limit the buffer to an arbitrary size then you need to change your approach to use dynamic memory (realloc or a linked list)
I am trying to take t (test cases) strings as inputs in C. Every string ends with a # and it can have spaces.
I am using getchar and some while loops but I am not able to achieve what I want.
int t;
scanf("%d",&t);
while(t>0){
char expression[100];
char c;
int i=0;
while(1){
c = getchar();
if(c == '#'){
break;
}
else{
expression[i]=c;
i++;
}
}
t--;
printf("%d\n",i);
for(int j=0;j<i;j++){
printf("%c",expression[j]);
}
}
What I am trying to achieve is if # is encountered I want to ignore whatever is after It.
My input:
1
test#wtf
Output:
5
test
So in case of 1 test case it is working fine.
But when I give try this.
2
test#wtf
test#
The corresponding outs are:
5
test
and
8
wtf
test
As you can see the second output should be test and length should be 5 but it is not so.
In order to ignore text after #, you'll have to consume those characters using getchar() and ignore them till you encounter a new line character '\n'.
So, after you exit the inner while loop, you need to add the following code
while(1) {
c = getchar();
if(c == '\n'){
break;
}
}
You can do it this way, you process all characters, once you get a '#' you keep reading characters without adding them to the array and you get out of the outer loop once you get a new line character '\n'.
while (--t > 0)
{
int i,s,c;
char exp[100];
s = 0;
while (s < 100 && (c = getchar()) != '#')
exp[s++] = c;
while ((c = getchar()) != '\n')
;
printf("%d\n", s);
i = -1;
while (++i < s)
printf("%c", exp[i]);
printf("\n");
}
I want to write a program which prints each letter with ASCII number.
The program should print 8 letters with ASCII number in one verse so I decide to make a counter and in each loop it should increment this variable.
The problem is more visible on this screenshot:
Why are spaces are not equal?
I think that something is wrong with loop.
My code:
int main(void) {
char ch;
int flag = 0;
while ((ch = getchar()) != '#') {
if (isalpha(ch)) {
flag++;
printf("%c : %d \t", ch, ch);
}
if ((flag % 8) == 0) {
printf("\n");
}
}
return 0;
}
Nothing wrong with the loop. its causes for extra " "(space) before \t. replace your first printf function with this:
printf("%c : %d\t", ch, ch);.
The spaces will be equal.
The loop is almost OK, you should more the test on flag inside the test on isalpha(c) otherwise you might print multiple newlines if the set of letters was not contiguous.
The alignment problem comes from the number of characters output before the TAB: "%c : %d \t" produces a single character for %c, 3 characters for :, up to 3 characters for %d, and another character for : that's 8 characters for c >= 100. The TAB character expands to the number of spaces needed to reach a column multiple of 8. Hence 1 space for c < 100 and 8 spaces for c >= 100.
You can fix this by removing the extra space before the \t.
Also note that you should read bytes from the input stream into an int variable and test for EOF too.
Here is a modified version:
int main(void) {
int ch;
int flag = 0;
while ((ch = getchar()) != EOF && c != '#') {
if (isalpha(ch)) {
printf("%c : %d\t", ch, ch);
flag++;
if ((flag % 8) == 0)
printf("\n");
}
}
return 0;
}
I am creating a program where I insert a number of sentences and the program outputs them in order. I have finished the program, but when I run it it seems like the characters I input into the array aren't displayed or stored correctly, getting as a result random letters instead of the full sentence. Here is the code of the program:
char ch;
int i,j,k;
int nothing = 0;
int count = 1;
char lines[5][256];
int length[256];
int main() {
printf("Please insert up to a max of 5 lines of text (Press enter to go to next line and twice enter to stop the program):\n");
i = 0;
while (i<5){
j = 0;
ch = getche();
if (ch == '\r'){
if(i!= 0){
break;
}
printf("You have not inserted anything, please insert a line:");
i=-1;
}
if(ch != '\r'){
lines[i][j]=ch;
while (ch!='\r'){
ch = getche();
lines[i][j] = ch;
j++;
}
}
printf("\n");
i++;
}
for (k=i ; k > 0; k--){
printf("\tphrase %i :", count);
for ( j =0 ; j <= length[k]; j++){
printf("%c",lines[j][k]);
}
count++;
printf("\n");
}
return 0;
}
How can I get the characters to be stored and displayed correctly? Any help is appreciated, thank you!!
There are numerous problems with your code. I'll try and summarise here, and give you improved code.
Fist, some changes that I made to get this to compile on my system:
Changed getche() to getchar() (getche() does not appear to be available on Ubuntu).
I took out the section about re-entering a string, and just focused on the rest (since the logic there was slightly broken, and not relevant to your question). It will still check for at least one line though, before it will continue.
I had to change the check for \r to \n.
I changed your length array to size 5, since you'll only have the lengths of maximum 5 strings (not 256).
Some problems in your code:
You never updated the length[] array in the main while loop, so the program never knew how many characters to print.
Arrays are zero indexed, so your final printing loops would have skipped characters. I changed the for parameters to start at zero, and work up to k < i, since you update i after your last character in the previous loop. The same with j.
Your reference to the array in the printing loop was the wrong way around (so you would've printed from random areas in memory). Changed lines[j][k] to lines[k][j].
No need for a separate count variable - just use k. Removed count.
The nothing variable does not get used - removed it.
#include <stdlib.h>
#include <stdio.h>
char ch;
int i,j,k;
char lines[5][256];
int length[5];
int main()
{
printf("Please insert up to a max of 5 lines of text (Press enter to go to the next line and twice enter to stop the program):\n");
i = 0;
while (i<5)
{
j = 0;
ch = getchar();
if ((ch == '\n') && (j == 0) && (i > 0))
{
break;
}
if (ch != '\n')
{
while (ch != '\n')
{
lines[i][j] = ch;
j++;
ch = getchar();
}
}
length[i] = j;
printf("\n");
i++;
}
for (k = 0; k < i; k++)
{
printf("\tPhrase %i : ", k);
for (j = 0; j < length[k]; j++)
{
printf("%c", lines[k][j]);
}
printf("\n");
}
return 0;
}
My task is:
Write a program that reads input up to # and reports the number of times that the sequence ei occurs.
I wrote something that in most of the times works, but there are inputs when it dosent...
Like this input:(suppose to return 1)
sdlksldksdlskd
sdlsklsdks
sldklsdkeisldksdlk
#
number of combination is: 0
This is the code:
int main(void)
{
int index = 0;
int combinationTimes = 0;
int total = 0;
char userInput;
char wordChar[index];
printf("please enter your input:\n");
while ((userInput = getchar()) != '#')
{
if (userInput == '\n')
continue;
wordChar[index] = userInput;
index++;
total++;
}
for (index = 1; index < total; index++)
{
if (wordChar[index] == 'i')
{
if (wordChar[--index] == 'e')
{
combinationTimes++;
++index;
}
}
}
printf("number of combination is: %d", combinationTimes);
return 0;
}
Can you please tell me what am I not getting 1 using this input?
in the book he said to test it with "Receive your eieio award" and it worked...but after i played with it a little i see that not always.
It really doesn't seem necessary to read the file into an array. You just need to keep track of how many times ei is found before you read a # or reach EOF:
#include <stdio.h>
int main(void)
{
int c;
int ei_count = 0;
while ((c = getchar()) != EOF && c != '#')
{
if (c == 'e')
{
int c1 = getchar();
if (c1 == 'i')
ei_count++;
else if (c1 != EOF)
ungetc(c1, stdin);
}
}
printf("ei appeared %d times\n", ei_count);
return(0);
}
Testing (the program is called ei and is built from ei.c):
$ ei < ei.c
ei appeared 0 times
$ sed 1d ei.c | ei
ei appeared 1 times
$ sed 's/#/#/' ei.c | ei
ei appeared 4 times
$
The first one stops at the #include line, the second stops at the # in the comparison, and the third reads the entire file. It also gives the correct output for the sample data.
Analysing the code
Your primary problem is that you do not allocate any space for the array. Change the dimension of the array from index to, say, 4096. That'll be big enough for your testing purposes (but really the program should pay attention to the array and not overflowing it — but then I don't think the array is necessary at all; see the code above).
The next primary problem is that despite its name, getchar() returns an int, not a char. It can return any valid character plus a distinct value, EOF. So it must return a value that's bigger than a char. (One of two things happens if you use char. If char is a signed type, some valid character — often ÿ, y-umlaut, U+00FF, LATIN SMALL LETTER Y WITH DIAERESIS — is also treated as EOF even though it is just a character. If char is an unsigned type, then no input matches EOF. Neither is correct behaviour.)
Fixing that is easy, but your code does not detect EOF. Always handle EOF; the data may be malformatted. That's a simple fix in the code.
A tertiary problem is that the printf() statement does not end with a newline; it should.
Your test condition here is odd:
if (wordChar[--index] == 'e')
{
combinationTimes++;
++index;
}
It's odd to use one pre-increment and one post-increment, but that's just a consistency issue.
Worse, though, is what happens when the character i appears in the input and is not preceded by e. Consider the line #include <stdio.h>: you start with index as 1; that is an i, so you decrement index, but wordChar[0] is not an e, so you don't increment it again, but the end of the loop does, so the loop checks index 1 again, and keeps on going around the loop testing that the i is i and # is not e for a long time.
There's no reason to decrement and then increment index; just use:
if (wordChar[index-1] == 'e')
combinationTimes++;
With those fixed, your code behaves. You trouble was largely that you were using an array that was not big enough (being size 0), and you were overwriting quasi-random memory with the data you were reading.
#include <stdio.h>
int main(void)
{
int index = 0;
int combinationTimes = 0;
int total = 0;
int userInput;
char wordChar[4096];
printf("please enter your input:\n");
while ((userInput = getchar()) != '#' && userInput != EOF)
{
if (userInput == '\n')
continue;
wordChar[index] = userInput;
index++;
total++;
}
printf("total: %d\n", total);
for (index = 1; index < total; index++)
{
if (wordChar[index] == 'i')
{
if (wordChar[index-1] == 'e')
combinationTimes++;
}
}
printf("number of combination is: %d\n", combinationTimes);
return 0;
}
Note that you could reasonably write the nested if as:
if (wordChar[index] == 'i' && wordChar[index-1] == 'e')
combinationTimes++;
change your wordChar array value.
int main(void)
{
int index = 0;
int combinationTimes = 0;
int total = 0;
char userInput;
//char wordChar[index]; // index = 0
char wordChar[255]; // should change the value of array.
printf("please enter your input:\n");
while ((userInput = getchar()) != '#')
{
if (userInput == '\n')
continue;
wordChar[index] = userInput;
index++;
total++;
}
for (index = 1; index < total; index++)
{
if (wordChar[index] == 'i')
{
if (wordChar[--index] == 'e')
{
combinationTimes++;
++index;
}
}
}
printf("number of combination is: %d", combinationTimes);
return 0;
}
or maybe you can use pointer and then use malloc and realloc.