The library of fmod is #include <cmath>
#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<map>
#include<cstring>
#include<cmath>
using namespace std;
int main(){
double x;
long y;
long long z;
scanf("%lf",&x);
double doubleMod = fmod(x,(double)3);
printf("The result of x mod 3 is %.2lf
",doubleMod);
scanf("%ld",&y);
printf("The result of y is %ld
", y);
scanf("%lld", &z);
printf("The result of z is %lld
", z);
return 0;
}cout << (-5) % 3 << endl; // 结果是-2!。。!!。!!
!!!!!
!!。!
!!
。!。!!
cout << fmod((double)(-5), (double)(-3))<<endl; //结果是-2!。!
!。!
!!!
!!
!!!!!