计算余数C++

题目：

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 代码：
 

#include<bits/stdc++.h>
using namespace std;
 
int main()
{
    double a, b;
 
    cin >> a >> b;
 
    assert(a> 0 && b > 0);
 
    int k = (int)(a/b);
    double r = a - k*b;
 
    cout << setiosflags(ios::fixed);
    cout << setprecision(2) << r << endl;
 
    return 0;
}