学步园

很裸的MST，没什么好说的

code：

/*
    ID:yueqi
    LANG:C++
    TASK:agrinet
*/
#include <set>
#include <map>
#include <ctime>
#include <queue>
#include <cmath>
#include <stack>
#include <limits.h>
#include <vector>
#include <bitset>
#include <string>
#include <cstdio>
#include <cstring>
#include <fstream>
#include <string.h>
#include <iostream>
#include <algorithm>
#define Si set<int>
#define LL long long
#define pb push_back
#define PS printf(" ")
#define Vi vector<int>
#define LN printf("\n")
#define lson l,m,rt << 1
#define rson m+1,r,rt<<1|1
#define SD(a) scanf("%d",&a)
#define PD(a) printf("%d",a)
#define SET(a,b) memset(a,b,sizeof(a))
#define FF(i,a) for(int i(0);i<(a);i++)
#define FD(i,a) for(int i(a);i>=(1);i--)
#define FOR(i,a,b) for(int i(a);i<=(b);i++)
#define FOD(i,a,b) for(int i(a);i>=(b);i--)
#define readf freopen("agrinet.in","r",stdin)
#define writef freopen("agrinet.out","w",stdout)
const int maxn = 101;
const long long BigP=999983;
const long long  INF = 0x5fffffff;
const int dx[]={-1,0,1,0};
const int dy[]={0,1,0,-1};
const double pi = acos(-1.0);
const double eps= 1e-7;
using namespace std;
int N,edge[maxn][maxn],dis[maxn];
bool vis[maxn];
void prim(int s){
    FOR(i,1,N) dis[i]=edge[1][i];
    dis[s]=0;
    vis[s]=true;
    int minn,ans=0;
    FOR(i,2,N){
        minn=INF;
        FOR(j,1,N){
            if(!vis[j]&&dis[j]<minn){
                minn=dis[j];
                s=j;
            }
        }
        ans+=minn;
        vis[s]=true;
        FOR(j,1,N){
            if(!vis[j]&&dis[j]>edge[s][j])
                dis[j]=edge[s][j];
        }
    }
    PD(ans);LN;
}
int main(){
    readf;
    writef;
    SD(N);
    FF(i,maxn) FF(j,maxn) edge[i][j]=INF;
    int w;
    FOR(i,1,N) FOR(j,1,N){
        SD(w);
        edge[i][j]=edge[j][i]=min(edge[i][j],w);
    }
    prim(1);
    return 0;
}