I - constructing roads

There are N villages, which are numbered from 1 to N, and you should build some roads such that every two villages can connect to each other. We say two village A and B are connected, if and only if there is a road between A and B, or there exists a village C such that there is a road between A and C, and C and B are connected.

We know that there are already some roads between some villages and your job is the build some roads such that all the villages are connect and the length of all the roads built is minimum.
Input
The first line is an integer N (3 <= N <= 100), which is the number of villages. Then come N lines, the i-th of which contains N integers, and the j-th of these N integers is the distance (the distance should be an integer within [1, 1000]) between village i and village j.

Then there is an integer Q (0 <= Q <= N * (N + 1) / 2). Then come Q lines, each line contains two integers a and b (1 <= a < b <= N), which means the road between village a and village b has been built.
Output
You should output a line contains an integer, which is the length of all the roads to be built such that all the villages are connected, and this value is minimum.
Sample Input
3
0 990 692
990 0 179
692 179 0
1
1 2
Sample Output
179
The question ：
Give a number n Indicates the number of villages
Next n*n Matrix ,map[i][j] The surface from the village i To the village j Distance of
One number on the next line k
Next k That's ok , Two numbers per line a,b, Indicate Village a To the village b The road has been built ,
Find the shortest circuit length to be repaired .
I'm a Han Han , I have been thinking that he gave me the distance between the two villages , It means no more calculation （ There is nothing wrong with that ）, But I am obsessed with how to ignore the given road when traversing the road , alas , After looking at other people's, I found that I could just let the road be 0, ahhhh , How simple , I'm really speechless to myself ！！！！！！

#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N=200,MAX=0x3f3f3f3f;
int n,m;
int from,to,w;
int dist[N],map[N][N];
bool biao[N];
int prim()
{
    
	memset(dist,0x3f,sizeof(dist));
	memset(biao,0,sizeof(biao));
	dist[1]=0,biao[1]=1;
	int t=1,sum=0;
	for(int i=0;i<n-1;i++)
	{
    
		for(int j=1;j<=n;j++)
		{
    
			dist[j]=min(dist[j],map[t][j]);
		}
		t=-1;
		for(int j=1;j<=n;j++)
		{
    
			if(!biao[j]&&(t==-1||dist[t]>dist[j]))
			t=j;
		}
		sum+=dist[t];
		biao[t]=1;
	}
	return sum;
}
int main()
{
    
	
  while(cin>>n)
  {
    
  		memset(map,0x3f,sizeof(map));
  		for(int i=1;i<=n;i++)
  		{
    
  			for(int j=1;j<=n;j++)
  			{
    
  				cin>>map[i][j];
			}
		  }
		  cin>>m;
  		while(m--)
  		{
    
  			int a,b;
  			cin>>a>>b;
  		map[a][b]=map[b][a]=0;

  			
		}
		int ans=prim();
		cout<<ans<<endl;
	
  }
    return 0;
}