为什么错了

#include <bits/stdc++.h>
using namespace std;
int n,m,a[101][21],pingjun[21],cnt[101];
int main(){
	scanf("%d%d",&n,&m);
	for(int i = 1;i<=n;i++)
		for(int j = 1;j<=m;j++)scanf("%d",&a[i][j]);
	for(int i = 1;i<=m;i++){
	    for(int j = 1;j<=n;j++)pingjun[i]+=a[j][i];
	    pingjun[i]/=n;
	    for(int j = 1;j<=n;j++)
	        if(a[j][i]>=pingjun[i])cnt[j]++;
	}
	for(int i = 1;i<=n;i++)printf("%d\n",cnt[i]);
	return 0;
}