小数计算器

#include<bits/stdc++.h>
using namespace std;
double a,b;
int main() {
    
    cin >> a >> b;
    double h = a + b;
    double m = a - b;
    double j = a * b;
    double z = a / b;
    cout << fixed << setprecision(2);
    cout << h << endl;
    cout << m << endl;
    cout << j << endl;
    cout << z << endl;
    return 0;
}

纳税

#include<bits/stdc++.h>
using namespace std;
int r;
int main()
{
	cin >> r;
	cout << fixed << setprecision(2);
	if (r<2000)
	{
		cout << 0.2*r;
	}
	else if(r>=2000 && r<4000)
	{
		cout << 0.3*r;
	}
	else
	{
		cout << 0.5*r;
	}
	return 0;
}

商场购物

#include<bits/stdc++.h>
using namespace std;
int a,b,num,c[10000];
int main()
{
	//大神，欢迎您在这里撸码~~
	cin >> a >> b;
	for(int i = 0;i<5;i++)
	{
		cin >> c[i];
		if(b>=c[i])
		{
			b=b-c[i];
		}
	}
	cout << b;
	return 0;
}