F - Truck History——最小生成树_Prim算法

#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;

const int inf = 0x3f3f3f3f;

int e[2014][2014], vis[2014], dis[2014];
char st[2014][14];

void Prim(int n);

int main(){
int n, i, j, k, cnt;
while(scanf("%d", &n) && n){
getchar();
for(i = 1; i <= n; i++)
scanf("%s", st[i]);
for(i = 1; i <= n; i++){
e[i][i] = 0;
for(j = i+1; j <= n; j++){
cnt = 0;
for(k = 0; k < 7; k++){
if(st[i][k] != st[j][k])
cnt++;
}
e[i][j] = e[j][i] = cnt;
}
}
Prim(n);
}
return 0;
}
void Prim(int n){
int i, miv, v, num, sum;
memset(vis, 0, sizeof(vis));
for(i = 1; i <= n; i++)
dis[i] = e[1][i];
vis[1] = 1, dis[1] = 0, num = 1, sum = 0;
while(num < n){
miv = inf;
for(i =1; i <= n; i++){
if(!vis[i] && dis[i] < miv){
miv = dis[i], v = i;
}
}
vis[v] = 1, num++, sum += dis[v];
for(i = 1; i <= n; i++){
if(!vis[i] && e[v][i] < dis[i])
dis[i] = e[v][i];
}
}
printf("The highest possible quality is 1/%d.\n", sum);
}