POJ1258 Agri-Net

/*
ID: LinKArftc
PROG: 1258.cpp
LANG: C++
*/

#include <map>
#include <set>
#include <cmath>
#include <stack>
#include <queue>
#include <vector>
#include <cstdio>
#include <string>
#include <utility>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
#define eps 1e-8
#define randin srand((unsigned int)time(NULL))
#define input freopen("input.txt","r",stdin)
#define debug(s) cout << "s = " << s << endl;
#define outstars cout << "*************" << endl;
const double PI = acos(-1.0);
const double e = exp(1.0);
const int inf = 0x3f3f3f3f;
const int INF = 0x7fffffff;
typedef long long ll;

const int maxn = 110;

int mp[maxn][maxn];
int dis[maxn];
bool vis[maxn];
int n;

int prim() {
    int ret = 0;
    for (int i = 2; i <= n; i ++) dis[i] = mp[i][1];
    dis[1] = 0;
    vis[1] = true;
    int ii = 1;
    for (int i = 2; i <= n; i ++) {
        int mi = inf;
        for (int j = 1; j <= n; j ++) {
            if (!vis[j] && dis[j] < mi) {
                mi = dis[j];
                ii = j;
            }
        }
        vis[ii] = true;
        ret += dis[ii];
        for (int j = 1; j <= n; j ++) {
            if (!vis[j] && dis[j] > mp[j][ii]) dis[j] = mp[j][ii];
        }
    }
    return ret;
}

int main() {

    //input;
    while (~scanf("%d", &n)) {
        memset(mp, 0x3f, sizeof(mp));
        memset(vis, 0, sizeof(vis));
        for (int i = 1; i <= n; i ++) {
            for (int j = 1; j <= n; j ++) scanf("%d", &mp[i][j]);
        }
        printf("%d\n", prim());
    }

    return 0;
}