poj1258
简单题
View Code
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;
#define inf 0x3f3f3f3f
#define maxn 105
int vis[maxn];
int lowc[maxn];
int cost[maxn][maxn];
int n;
void input()
{
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++)
scanf("%d", &cost[i][j]);
}
int prim()
{
int i, j, p;
int minc, res = 0;
memset(vis, 0, sizeof(vis));
vis[0] = 1;
for (i = 0; i < n; i++)
lowc[i] = cost[0][i];
for (i = 1; i < n; i++)
{
minc = inf;
p = -1;
for (j = 0; j < n; j++)
if (0 == vis[j] && minc > lowc[j])
{
minc = lowc[j];
p = j;
}
if (inf == minc)
return -1;
res += minc;
vis[p] = 1;
for (j = 0; j < n; j++)
if (0 == vis[j] && lowc[j] > cost[p][j])
lowc[j] = cost[p][j];
}
return res;
}
int main()
{
//freopen("t.txt", "r", stdin);
while (scanf("%d", &n) != EOF)
{
input();
printf("%d\n", prim());
}
return 0;
}