不知道为什么数据小数点后全没了，求助！

#include <bits/stdc++.h>
using namespace std;

int stu[101][21], n, m, pinjunn[101];

double maxa(int a[], int b) {
	double maxn = -32768;

	for(int i = 0; i < b; ++i) {
		if (a[i] > maxn) {
			maxn = a[i];
		}
	}
	
	return maxn;
}

double mina(int a[], int b) {
	double minn = 32768;

	for(int i = 0; i < b; ++i) {
		if (a[i] < minn) {
			minn = a[i];
		}
	}
	
	return minn;
}

double pinjun(int a[], int b) {
	for (int i = 0; i < b; ++i) {
		if (a[i] == maxa(a, b)) {
			a[i] = 0;
			break;
		}
	}
	
	for (int i = 0; i < b; ++i) {
		if (a[i] == mina(a, b)) {
			a[i] = 0;
			break;
		}
	}	
	
	int ans = 0;
	
	for (int i = 0; i < b; ++i) {
		ans += a[i];
	}
	
	return 1.0 * ans / (b - 2);
	
}

int main() {
	cin >> n >> m;
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < m; ++j) {
			cin >> stu[i][j];
		}
	}
	
	for (int i = 0; i < n; ++i) {
		pinjunn[i] = pinjun(stu[i], m);
	}
	
	printf("%.2lf", maxa(pinjunn, n));
	
	return 0;
}