Generate all possible combinations between 00000000 and 99999999 and write into a file

[topaz lantern]

Hello, I would like to generate all the possible combinations of the number "00000000" to "99999999" and write them to a file, for this I have made this code, but it does not work and no error is thrown. Could you help me more to find the problem please? Maybe I do it the wrong way. Thank you ^^

#include <stdio.h>
#include <stdlib.h>


int main(void) {
    FILE* fp;

    fp = fopen("numlist.txt", "a");

    for (int a = 0; a < 10; a++) {
        for (int b = 0; b < 10; b++) {
            for (int c = 0; c < 10; c++) {
                for (int d = 0; d < 10; d++) {
                    for (int d = 0; d < 10; d++) {
                        for (int e = 0; e < 10; e++) {
                            for (int f = 0; f < 10; f++) {
                                for (int g = 0; g < 10; g++) {
                                    for (int h; h < 10; h++) {
                                        fprintf(fp, "%d%d%d%d%d%d%d%d;", a, b, c, d, e, f, g, h);
                                    }
                                }
                            }                    
                        }
                    }
                }
            }
        }
    }
    return EXIT_SUCCESS;
}

[dreamy rune]

When your question is answered use !solved to mark the question as resolved.

Remember to ask specific questions, provide necessary details, and reduce your question to its simplest form. For more information use !howto ask.

[topaz lantern]

Maybe it is too much ? (10^8) * 9 chars would be too much ?

[glossy adder]

;cpp << log10(99999999)

[wet dawn]

Program Output

8

jr-#6677 | 45ms | g101 | godbolt.org

[glossy adder]

9 * 100 million, you're looking at 900 MB

It's a lot but not too much

[topaz lantern]

👍

[glossy adder]

Maybe try "w" instead of "a" though

[topaz lantern]

ok i will try 🙂

[glossy adder]

Assert that fopen and fprintf aren't failing, don't forget to fclose

[topaz lantern]

This is returned by the fprintf on each iter

10;10;10;10;10;10;10;10;10;10;%

#include <stdio.h>
#include <stdlib.h>


int main(void) {
    FILE* fp;

    fp = fopen("numlist.txt", "w");

    if (fp == NULL) {
        printf("Can't open file");
        exit(1);
    }
    for (int a = 0; a < 10; a++) {
        for (int b = 0; b < 10; b++) {
            for (int c = 0; c < 10; c++) {
                for (int d = 0; d < 10; d++) {
                    for (int d = 0; d < 10; d++) {
                        for (int e = 0; e < 10; e++) {
                            for (int f = 0; f < 10; f++) {
                                for (int g = 0; g < 10; g++) {
                                    for (int h; h < 10; h++) {
                                        int fpf = fprintf(fp, "%d%d%d%d%d%d%d%d", a, b, c, d, e, f, g, h);
                                        printf("%d;", fpf);
                                    }
                                }
                            }                    
                        }
                    }
                }
            }
        }
    }
    fclose(fp);
    return EXIT_SUCCESS;
}

(The thing i made to see)

[tame linden]

Why would you do it with so many nested for-loops?
Just do:

for (int i = 0; i < 99999999; ++i)
    fprintf(fp, "%08d", i);

;compile

for (int i = 0; i < 10; ++i)
    printf("%08d\n", i);

[wet dawn]

Program Output

00000000
00000001
00000002
00000003
00000004
00000005
00000006
00000007
00000008
00000009

Samu#6425 | 46ms | c | x86-64 gcc 12.2 | godbolt.org

[topaz lantern]

You're right !

I'm so stupid

Thank you very much !!

!solved

[dreamy rune]

Thank you and let us know if you have any more questions!

[SOLVED] Generate all possible combinations between 00000000 and 99999999 and write into a file