P5709 【深基2.习6】Apples Prologue / 苹果和虫子

题目传送门

#include 

using namespace std;

int main() {
    int m, t, s;
    cin >> m >> t >> s;
    if(t==0) {
        printf("0");
        return 0;
    }
    int x = ceil(1.0 * s / t);
    if (m <= x) printf("%d", 0);
    else printf("%d", m - x);
    return 0;
}