最小生成树 prime poj1287

poj1287 裸最小生成树

代码

#include "map"
#include "queue"
#include "math.h"
#include "stdio.h"
#include "string.h"
#include "iostream"
#include "algorithm"
#define abs(x) x > 0 ? x : -x
#define max(a,b) a > b ? a : b
#define min(a,b) a < b ? a : b

using namespace std;

int arc[55][55];

void Prime(int n){
    int i,j,k,m;
    int sumweight = 0;
    int addnew[55];
    int lowcost[55];
    for(i=1; i<=n; i++){
        addnew[i] = 0;
        lowcost[i] = arc[1][i];
    }
    addnew[1] = 1;
    for(i=1; i<n; i++){
        k = 0,m = 999999;
        for(j=2; j<=n; j++){
            if(!addnew[j] && lowcost[j]<m){
                m = lowcost[j];
                k = j;
            }
        }
        sumweight += lowcost[k];
        addnew[k] = 1;
        for(j=2; j<=n; j++){
            if(!addnew[j] && arc[k][j]<lowcost[j])
                lowcost[j] = arc[k][j];
        }
    }
    printf("%d\n",sumweight);
}

int main(){
    int n,m,i,a,b,c;
    while(scanf("%d",&n)&&n){
        memset(arc,111,sizeof(arc));
        scanf("%d",&m);
        while(m--){
            scanf("%d%d%d",&a,&b,&c);
            if(arc[a][b]>c){
                arc[a][b] = c;
                arc[b][a] = c;
            }
        }
        Prime(n);
    }
    return 0;
}