四舍五入小技巧

对小数点后第4为四舍五入

d = (d*10000+0.5)/10000.0;

PAT B 1077 互评成绩计算

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <vector>
using namespace std;
int main()
{
	int n, m;
	cin >> n >> m;
	vector<double> ans;
	for (int i = 0; i < n; i++)
	{
		double sum_gp = 0;
		int techer, temp;
		vector<int> gp;
		cin >> techer;
		for (int j = 0; j < n-1; j++)
		{
			cin >> temp;
			if (temp >= 0 && temp <= m) {
				gp.push_back(temp);
			}
		}
		sort(gp.begin(), gp.end());
		for (int j = 1; j <= gp.size()-2; j++)
		{
			sum_gp += gp[j];
		}
		ans.push_back((techer + (sum_gp / (gp.size() - 2)) ) / 2.0);
	}
	for (int i = 0; i < n; i++)
	{
		printf("%d\n",(int) (ans[i]+0.5));
		
	}
}