poj-1251 Jungle Roads *

/*
 * 1251.cpp
 * 纯粹MST。。  Prim实现
 *
 *  Created on: 2011-9-2
 *      Author:
 *
 *      开始用scanf， WA， 后改成cin， AC了~ 不知怎么回事 总之对C的输入输出理解的还不够好~
 */
#include <cstdio>
#include <iostream>
usingnamespace std;

constint maxN =27+5;
constint inf =100000000;
int n, w[maxN][maxN], d[maxN], ans;
intbase='A'-1;

int inline min(int lhs, int rhs){
    return lhs < rhs ? lhs : rhs;
}

//同1258的模板~
int mstPrim(){
    for(int i=1; i<=n; i++)
        d[i] = inf;

    int cur =1, minEdge, minNode;
    ans =0;

    for(int i=1; i<n; i++){
        d[cur] =-1;
        minEdge = inf;
        for(int j=1; j<=n; j++){
            if(cur != j && d[j] !=-1){
                d[j] = min(d[j], w[cur][j]);
                if(d[j] < minEdge){
                    minEdge = d[j]; minNode = j;
                }
            }
        }

        cur = minNode;
        ans += minEdge;
    }

    return ans;
}




int main(){
    while(cin >> n){

        if(n==0) return0;

        for(int i=1; i<=n; i++){
            for(int j=1; j<=n; j++)
                w[i][j] = inf;
        }


        char curNode, nextNode;
        int edgeNum, edgeW, iCurNode, iNextNode;
        for(int i=1; i<n; i++){
            //scanf("%s%d", &curNode, &edgeNum);
            cin >> curNode >> edgeNum;
            iCurNode  = curNode -base;

            for(int j=1; j<=edgeNum; j++){
            //    scanf("%s%d", &nextNode, &edgeW);
                cin >> nextNode >> edgeW;

                iNextNode  = nextNode -base;

                w[iCurNode][iNextNode] = w[iNextNode][iCurNode] = edgeW;

            }
        }

        mstPrim();

        printf("%d\n", ans);

    }


    return0;
}

 

/*
 * DA-term-Main-Mirror3.cpp.cpp
 *　　
　　scanf 用%s即可

 *  Created on: 2011-12-8
 *   
 */

#include <cstdio>
#include <algorithm>
using namespace std;

const int maxn = 27 + 5;
const int maxE = 75 + 5;

int n, edgeNum;

struct SEdge{
    int w;
    char u, v;
};
SEdge edge[maxE];

struct SData{
    char name;
    char p;
    int num;
};
SData node[maxn];


bool inline cmp(const SEdge a, const SEdge b){
    return a.w < b.w;
}

char find(char cur){
    if(node[cur-'A'].p == cur)
        return cur;

    node[cur-'A'].p = find(node[cur-'A'].p);
    return node[cur-'A'].p;
}

void merge(char u, char v){
    int up = find(u);
    int vp = find(v);
    if(up == vp) return;

    if(node[up-'A'].num < node[vp-'A'].num){
        node[up-'A'].p = vp;
        node[vp-'A'].num += node[up-'A'].num;
    }
    else{
        node[vp-'A'].p = up;
        node[up-'A'].num += node[vp-'A'].num;
    }
}



int kruskal(){
    sort(edge, edge+edgeNum, cmp);

    int ans = 0;
    for(int i=0; i<edgeNum; i++){
        if(find(edge[i].u) == find(edge[i].v))
            continue;
        merge(edge[i].u, edge[i].v);
        ans += edge[i].w;
    }
    return ans;
}


int main(){
    char tmpName[2], nextName[2];
    int tmpW, tmpNum;

    while(scanf("%d", &n), n){
        for(int i=0; i<n; i++){
            node[i].p = 'A' + i;
            node[i].num = 1;
        }
        edgeNum = 0;

        for(int i=0; i<n-1; i++){
            scanf("%s%d", tmpName, &tmpNum);

            for(int j=0; j<tmpNum; j++){
                scanf("%s%d", nextName, &tmpW);

                edge[edgeNum].w = tmpW;
                edge[edgeNum].u = tmpName[0];
                edge[edgeNum++].v = nextName[0];
            }

        }

        int ans = kruskal();
        printf("%d\n", ans);
    }




    return 0;
}