CodinGame_2023_08_21__22_07_45__factorial.c

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

long fact(int n);

/**
 * Auto-generated code below aims at helping you parse
 * the standard input according to the problem statement.
 **/

int main()
{
    int N;
    scanf("%d", &N);

    // Write an answer using printf(). DON'T FORGET THE TRAILING \n
    // To debug: fprintf(stderr, "Debug messages...\n");
    if (N < 0) {
        printf("No negative integers");
    } else {
        printf("%ld\n", fact(N));
    }

    return 0;
}

long fact(int n) {
    if (n == 0 || n == 1) return 1;
    return n * fact(n-1);
}