代码献上

#include<bits/stdc++.h>
using namespace std;
int maps[1010][1010],queues[1000010],a,b,i,j,n,cnt;
int main()
{
    cin>>a>>b;
    for(i=1;i<=b;i++)
    	for(j=1;j<=b;j++)
		{
			cin>>maps[i][j];
			if(!maps[i][j]) maps[i][j]=a;
		} 
	for(i=1;i<=b;i++) for(j=i;j<=b;j++) queues[n++]=maps[i][j];
	sort(queues,queues+n);
	for(i=0;i<b;i++) cnt+=queues[i];
	cout<<cnt;
}