I'm new to C programming language and I'm having a really difficult time trying to do this:
I have a file .txt created by my program that store the leaderboard of the 2048 game that I'm doing, and I think that the easiest way to make the leaderboard is by appending the result to the end of the file and than doing a bubble sort, but I can't find the correct value (score) of the first place to compare with the next place, and so on.
Here is my code:
FILE* ptr;
prt = fopen("Placar.txt", "a");
if(ptr == NULL)
{
printf("Error!");
}
fclose(ptr);
ptr = fopen("Placar.txt", "r");
int ch, lines = 0, aux;
char line[150];
while(!feof(ptr))
{
ch = fgetc(ptr);
if (ch == '\n')
{
lines++;
}
}
fclose(ptr);
ptr = fopen("Placar.txt", "a");
fprintf(ptr, "%d: Name: %s - Score: %d - Movements: %d\n", lines+1, name, score, movements);
fclose(ptr);
// bubble sort
ptr = fopen("Placar.txt", "r+");
for (int i = 0; i < 10; i++)
{
for (int j = 0; j < 10; j++)
{
while (!feof(ptr))
{
fgets(line, 150, ptr);
if (strstr(linha, "Score: ") != NULL)
{
// dont know how to do
}
}
}
}
fclose(ptr);
// TODO: delete the 11th line to make the top 10 only
If you think that I'm overcomplicating this, let me know how would you do.
Thanks for the help.
I think that the easiest way to make the leaderboard is by appending the result to the end of the file and than doing a bubble sort
I don't think that's easiest at all. It's especially bad if, as appears to be the case, you have in mind to use the file as your workspace instead of reading the contents into memory, sorting there, and then writing the results back out.
If you think that I'm overcomplicating this, let me know how would you do.
Consider this alternative:
open the high-score file and a temporary file
read scores from the original file one by one and write them to the temp file, until you find the first that is less than the new score you are recording (or reach the end of the file)
write the new score to the temp file
copy the rest of the scores from the original file to the temp file
close both files and replace the original with the temp file.
That involves at most all the same reading, at most all the same writing, and no sorting except for just inserting the new score at the correct place in the sequence. If you like, you can consider it a variation on Insertion Sort. As a bonus, it also has the same, minimal, storage requirements no matter how many scores there are, and therefore does not require any dynamic memory allocation.
Related
#EDIT: I think the problem is that I put my 2 text files on desktop. Then, I move them to the same place as the source file and it works. But the program cannot run this time, the line:
cok = 0;
shows "exception thrown".
// end EDIT
I have the assignment at school to write a C program to create 2 text files. 1 file stores 25 keywords, and 1 file stores the fake resume. The problem is, my program cannot read my keywords.txt file. Anyone can help me? Thank you so much.
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//*****************************************************
// MAIN FUNCTION
int main()
{
//File pointer for resume.txt file declared
FILE *fpR;
//File pointer for keywords.txt file declared and open it in read mode
FILE* fpK = fopen("keywords.txt", "r");
//To store character extracted from keyword.txt file
char cK;
//To store character extracted from resume.txt file
char cR;
//To store word extracted from keyword.txt file
char wordK[50];
//To store word extracted from resume.txt file
char wordR[50];
//To store the keywords
char keywords[10][50];
//To store the keywords counter and initializes it to zero
int keywordsCount[10] = { 0, 0, 0, 0 };
int coK, coR, r, r1;
coK = coR = r = r1 = 0;
//Checks if file is unable to open then display error message
if (fpK == NULL)
{
printf("Could not open files");
exit(0);
}//End of if
//Extracts a character from keyword.txt file and stores it in cK variable and Loops till end of file
while ((cK = fgetc(fpK)) != EOF)
{
//Checks if the character is comma
if (cK != ',')
{
//Store the character in wordK coK index position
wordK[coK] = cK;
//Increase the counter coK by one
coK++;
}//End of if
//If it is comma
else
{
//Stores null character
wordK[coK] = '\0';
//Copies the wordK to the keywords r index position and increase the counter r by one
strcpy(keywords[r++], wordK);
//Re initializes the counter to zero for next word
coK = 0;
fpR = fopen("resume.txt", "r");
//Extracts a character from resume.txt file and stores it in cR variable and Loops till end of file
while ((cR = fgetc(fpR)) != EOF)
{
//Checks if the character is space
if (cR != ' ')
{
//Store the character in wordR coR index position
wordR[coR] = cR;
//Increase the counter coR by one
coR++;
}//End of if
else
{
//Stores null character
wordR[coR] = '\0';
//Re initializes the counter to zero for next word
coR = 0;
//Compares word generated from keyword.txt file and word generated from resume.txt file
if (strcmp(wordK, wordR) == 0)
{
//If both the words are same then increase the keywordCounter arrays r1 index position value by one
keywordsCount[r1] += 1;
}//End of if
}//End of else
}//End of inner while loop
//Increase the counter by one
r1++;
//Close the file for resume
fclose(fpR);
}//End of else
}//End of outer while loop
//Close the file for keyword
fclose(fpK);
//Display the result
printf("\n Result \n");
for (r = 0; r < r1; r++)
printf("\n Keyword: %s %d time available", keywords[r], keywordsCount[r]);
}//End of main
I think the problem is the text files, aren't they?
The name of my 1st test file is "keywords.txt", and its content is:
Java, CSS, HTML, XHTML, MySQL, College, University, Design, Development, Security, Skills, Tools, C, Programming, Linux, Scripting, Network, Windows, NT
The name of my 2nd test file is "resume.txt", and its content is:
Junior Web developer able to build a Web presence from the ground up -- from concept, navigation, layout, and programming to UX and SEO. Skilled at writing well-designed, testable, and efficient code using current best practices in Web development. Fast learner, hard worker, and team player who is proficient in an array of scripting languages and multimedia Web tools. (Something like this).
I don't see any problem with these 2 files. But my program still cannot open the file and the output keeps showing "Could not open files".
while ((cK = fgetc(fpK)) != EOF)
If you check the documentation, you can see that fgets returns an int. But since cK is a char, you force a conversion to char, which can change its value. You then compare the possibly changed value to EOF, which is not correct. You need to compare the value that fgets returns to EOF since fgetc returns an EOF on end of file.
I have scanned "ABCDEFGHIJK" with fscanf into a char array[26]. Then I got "ABCDEFGHIJK" using "for" into another array[11]. Now I need to get to an "ABCDEFGHIJK.mp4" array[15] in order to feed that filename into a rename function.
I don't know much about C programming besides printf, scanf, for and while.
sprintf(filename, "%c%c%c%c%c%c%c%c%c%c%c.mp4", codigo[0], codigo[1], codigo[2], codigo[3], codigo[4], codigo[5], codigo[6], codigo[7], codigo[8], codigo[9], codigo[10]);
This code above seems to work, but I wonder if there is a simpler way (especially for bigger arrays)?
Clarification: I have a txt file, formatted with these containing the filenames without extension and the human filename. I'm trying to make a program that will rename these files to the correct name, as they are from a backup that failed.
EDIT: Here is the full program. I renamed the variables to make more sense, so "codigo" is now "idcode".
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void)
{
int i, j, k;
char value1[26], value2[70], idcode[11], filename[16], fullname[64], filenamestring[16], fullnamestring[64];
// Opening file.
FILE *nomes;
nomes = fopen("/Users/EA/Desktop/Songs/backup.txt", "rt");
if(nomes == NULL)
{
printf("Erro ao abrir backup.txt");
exit(1);
}
// Skipping beggining of file until first value.
for(i=0; i<10; i++)
{
fscanf(nomes, "%*s");
}
// Reading first value, and repetition.
while(fscanf(nomes, "%s", value1) == 1)
{
j = k = 0;
// Extracting idcode from value1.
for(i=7; i<18; i++)
{
idcode[j] = value1[i];
j++;
}
// Filling the complete filename.
sprintf(filename, "%.*s.mp4", 11, idcode);
// Reading second value, the "human" filename.
fscanf(nomes, "\n%[^\n]", value2);
for(i=6; i<70; i++)
{
fullname[k] = value2[i];
k++;
}
// Transforming filenames into strings for rename function.
strncpy(filenamestring, filename, 16);
strncpy(fullnamestring, fullname, 64);
// Renaming the files.
rename(filename, fullname);
// Skipping useless data before the next cycle.
for(i=0; i<9; i++)
{
fscanf(nomes, "%*s");
}
}
// Closing file and ending program.
fclose(nomes);
return(0);
}
It looks like you got an array of char's.
You can simply do:
sprintf(filename, "%.*s.mp4", 11, codigo)
You can read more about the %.*s specifier in this question.
If you just want to append the format ".mp4" to the end of the string the easiest way to do that is just:
strcat(filename,".mp4");
after you printed the name without the ".mp4" into it.
If you really want to use sprintf then i think this should suffice:
sprintf(filename,"%s.mp4", codigo);
Also,if you want your string to be bigger and not fixed in size you can put "\0" at the end of it(this might not work if you try to use the strings in other programming languages but c) with strcat as above,or you can do this:
memset(&filename, 0, sizeof(filename));
I have written the following function in my C program. The program loads a text file (Les Miserables Vol. I) as well as another text file of 20 of the characters names. The purpose of this function is to scan the entire file, line by line, and count the number of times any of the 20 names appear.
NumOfNames = 20.
Names is an array of the 20 names stored from Names[1] - Names[20].
MaxName is a global integer variable which I would like to store the total number of name appearances throughout the file (It should be in the hundreds or even thousands).
EDIT: After the function is executed, the value of MaxName is 4. I am completely lost as to where I have made a mistake, but it appears that I have made several mistakes throughout the function. One seems to be that it only executed the first iteration of the for loop i.e. it only searches for Name[1], however the first name appears 196 times in the file, so it still isnt even working correctly for just the first name.
void MaxNameAppearances()
{
char LineOfText[85];
char *TempName;
FILE *fpn = fopen(LesMisFilePath, "r+");
for(i = 1; i<=NumOfNames; i++)
{
while(fgets(LineOfText, sizeof(LineOfText), fpn))
{
TempName = strstr(LineOfText, Names[i]);
if(TempName != NULL)
{
MaxName++;
}
}
}
fclose(fpn);
}
I guess that one problem of the code is that it would have to read the file upon every iteration of i. Try to re-order the loops like this:
while(fgets(LineOfText, sizeof(LineOfText), fpn))
{
for(i = 1; i<=NumOfNames; i++)
{
TempName = strstr(LineOfText, Names[i]);
if(TempName != NULL)
{
MaxName++;
}
}
}
This reads a line, checks the occurrances of all names in that line and then goes on to the next line.
If you do it your way, you will be at the end of file for i == 1 already.
I wrote this program for my C class. It basically takes the user to a horse track, display odds on different horses and allows the user to make a bet. Originally, my instructor only wanted us to write the results to a text or binary file, so the past results could be viewed whenever the user wanted.
He recently told us that he wants us to include bubble sort to group the horses in order i.e. horse 1, horse 1, horse 1, horse 1, horse 2, horse 2...etc.
I am sure I can figure out the bubble sort using strcmp(), but he also wants us to display how many times that horse has won the race in the past.
My question is: will I be able to make such a display dealing only with char/string arrays? I don't want to spend my next four hours building a solution that cannot work.
Thanks in advance,
p.s. Here is the function for that part of the program.
void viewWinners() {
FILE *zacksTrackStats;
char horses[MAX_SIZE] = {0};
if ((zacksTrackStats = fopen("zacksTrackStats.txt", "r")) == NULL)
{
perror ("error");
exit (0);
}
while (fgets(horses, sizeof(horses), zacksTrackStats) != NULL)
{
printf ("%s", horses);
}
fclose(zacksTrackStats);
pause;
}
Of course you can. Are the actual names "horse 1" and "horse 2"? If so you can just store each horse's data in an integer array. If not then you have to make a lookup table. Store information for how many times each horse has won and print the result.
It is entirely possible to translate txt to numbers and vice versa.
Check out this older post:
Converting string to integer C
Yes you can. To manipulate data from the file you can use fscanf (or sscanf).
sscanf(char *source, format, &dest, ...)
For example :
int occurences[NUMBER_OF_HORSES_MAX];
int count = 0;
int temp = 0;
int i;
for(i = 0; i < NUMBER_OF_HORSES_MAX; ++i)
{
occurences[i] = 0;
}
while (fgets(horses, sizeof(horses), zacksTrackStats) != NULL)
{
sscanf(horses, "%d", &temp);
occurences[temp] += 1;
printf ("Current horse : %s", horses);
count++;
}
for(i = 0; i < count; ++i)
{
printf("Horse %d has won %d times\n", i, occurences[i]);
}
I'm making a small console-based rpg, to brush up on my programming skills.
I am using structures to store character data. Things like their HP, Strength, perhaps Inventory down the road. One of the key things I need to be able to do is load and save characters. Which means reading and saving structures.
Right now I'm just saving and loading a structure with first name and last name, and attempting to read it properly.
Here is my code for creating a character:
void createCharacter()
{
char namebuf[20];
printf("First Name:");
if (NULL != fgets(namebuf, 20, stdin))
{
char *nlptr = strchr(namebuf, '\n');
if (nlptr) *nlptr = '\0';
}
strcpy(party[nMember].fname,namebuf);
printf("Last Name:");
if (NULL != fgets(namebuf, 20, stdin))
{
char *nlptr = strchr(namebuf, '\n');
if (nlptr) *nlptr = '\0';
}
strcpy(party[nMember].lname,namebuf);
/*Character created, now save */
saveCharacter(party[nMember]);
printf("\n\n");
loadCharacter();
}
And here is the saveCharacter function:
void saveCharacter(character party)
{
FILE *fp;
fp = fopen("data","a");
fwrite(&party,sizeof(party),1,fp);
fclose(fp);
}
and the loadCharacter function
void loadCharacter()
{
FILE *fp;
character tempParty[50];
int loop = 0;
int count = 1;
int read = 2;
fp= fopen("data","r");
while(read != 0)
{
read=fread(&tempParty[loop],sizeof(tempParty[loop]),1,fp);
printf("%d. %s %s\n",count,tempParty[loop].fname,tempParty[loop].lname);
loop++;
count++;
}
fclose(fp);
}
So the expected result of the program is that I input a name and last name such as 'John Doe', and it gets appended to the data file. Then it is read in, maybe something like
1. Jane Doe
2. John Doe
and the program ends.
However, my output seems to add one more blank structure to the end.
1. Jane Doe
2. John Doe
3.
I'd like to know why this is. Keep in mind I'm reading the file until fread returns a 0 to signify it's hit the EOF.
Thanks :)
Change your loop:
while( fread(&tempParty[loop],sizeof(tempParty[loop]),1,fp) )
{
// other stuff
}
Whenever you write file reading code ask yourself this question - "what happens if I read an empty file?"
You have an algorithmic problem in your loop, change it to:
read=fread(&tempParty[loop],sizeof(tempParty[loop]),1,fp);
while(read != 0)
{
//read=fread(&tempParty[loop],sizeof(tempParty[loop]),1,fp);
printf("%d. %s %s\n",count,tempParty[loop].fname,tempParty[loop].lname);
loop++;
count++;
read=fread(&tempParty[loop],sizeof(tempParty[loop]),1,fp);
}
There are ways to ged rid of the double fread but first get it working and make sure you understand the flow.
Here:
read=fread(&tempParty[loop],sizeof(tempParty[loop]),1,fp);
printf("%d. %s %s\n",count,tempParty[loop].fname,tempParty[loop].lname);
You are not checking whether the read was successful (the return value of fread()).
while( 1==fread(&tempParty[loop],sizeof*tempParty,1,fp) )
{
/* do anything */
}
is the correct way.
use fopen("data","rb")
instead of fopen("data","r") which is equivalent to fopen("data","rt")
You've got the answer to your immediate question but it's worth pointing out that blindly writing and reading whole structures is not a good plan.
Structure layouts can and do change depending on the compiler you use, the version of that compiler and even with the exact compiler flags used. Any change here will break your ability to read files saved with a different version.
If you have ambitions of supporting multiple platforms issues like endianness also come into play.
And then there's what happens if you add elements to your structure in later versions ...
For robustness you need to think about defining your file format independently of your code and having your save and load functions handle serialising and de-serialising to and from this format.