L - Jungle roads (minimum spanning tree)

#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N=200,MAX=0x3f3f3f3f;
int n;
int from,to,w;
int dist[N],map[N][N];
bool biao[N];
int prim()// Algorithm part template  
{
    
	memset(dist,0x3f,sizeof(dist));
	memset(biao,0,sizeof(biao));
	int t=1,sum=0;
	dist[1]=0,biao[1]=1;
	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&&n)
 {
    
 	int t=n-1;
 	memset(map,0x3f,sizeof(map));
 	while(t--)
 	{
    
 		char c;
 		cin>>c;
 		int kk=c-'A'+1;// Convert characters into numbers as soon as you enter them , 
 		int m;
 		cin>>m;
 		while(m--)
 		{
    
 			char cc;
 			int mm;
 			cin>>cc;
 			int ll=cc-'A'+1;
 			cin>>mm;
 			map[kk][ll]=map[ll][kk]=mm;// The path should be bidirectional 
		 }
	}
	int sum=prim();
	cout<<sum<<endl;
	
 }
    return 0;
}

The question ：
It is still to find the minimum path length ,
But the peculiar thing about this topic is , The place is indicated by letters , But that's okay , Then turn it into numbers again , How wise