11934 Magic Formula

程式碼

#include <stdio.h>
int main() {
    // f(x) = ax^2 + bx + c
    int count = 0, a, b, c, d, l, x;
    scanf("%d %d %d %d %d", &a, &b, &c, &d, &l);
    for (int i = 1; i < l; i++) {
        if ((a * i * i + b * i + c) % d == 0) {
            count = count + 1;
        }
    }
    printf("%d", count);
    return 0;
}