hdu 2112赤裸裸的最短路

赤裸裸的，需要注意的是这题是无向图，有重边，且起点可能与终点相同，这些是容易WA的地方。

/*

 * hdu2112/win.cpp

 * Created on: 2012-8-2

 * Author    : ben

 */

#include <cstdio>

#include <cstdlib>

#include <cstring>

#include <cmath>

#include <ctime>

#include <iostream>

#include <algorithm>

#include <queue>

#include <set>

#include <stack>

#include <string>

#include <vector>

#include <deque>

#include <list>

#include <functional>

#include <numeric>

#include <cctype>

using namespace std;

int N, M;

const int SIZE = 160;

typedef int typec;

const typec MAX = 0x7fffffff;

typec map[SIZE][SIZE];

char stations[SIZE][40];

typec dijistra(int s, int e) {

    int i, j, k;

    typec mind, minf, D[SIZE];

    bool visited[SIZE];

    for (i = 0; i < N; i++) {

        visited[i] = false;

        D[i] = map[s][i];

    }

    visited[s] = 1;

    D[s] = 0;

    for (i = 1; i < N; i++) {

        mind = MAX;

        minf = MAX;

        k = 0;

        for (j = 0; j < N; j++) {

            if (visited[j]) {

                continue;

            }

            if (D[j] < mind) {

                k = j;

                mind = D[j];

            }

        }

        visited[k] = true;

        for (j = 0; j < N; j++) {

            if (!visited[j]) {

                if (D[k] < D[j] - map[k][j]) {

                    D[j] = D[k] + map[k][j];

                }

            }

        }

    }

    return D[e];

}



int getindex(const char *name) {

    for(int i = 0; i < N; i++) {

        if(strcmp(name, stations[i]) == 0) {

            return i;

        }

    }

    strcpy(stations[N], name);

    return N++;

}



void init() {

    for (int i = 0; i < SIZE; i++) {

        for (int j = 0; j < SIZE; j++) {

            map[i][j] = MAX;

        }

    }

}



int main() {

#ifndef ONLINE_JUDGE

    freopen("data.in", "r", stdin);

#endif

    char ts[40];

    int t, a, b, s, e;

    while(scanf("%d", &M) == 1 && M > 0) {

        init();

        N = 0;

        scanf("%s", ts);

        s = getindex(ts);

        scanf("%s", ts);

        e = getindex(ts);

        for(int i = 0; i < M; i++) {

            scanf("%s", ts);

            a = getindex(ts);

            scanf("%s", ts);

            b = getindex(ts);

            scanf("%d", &t);

            if(t < map[a][b]) {

                map[a][b] = map[b][a] = t;

            }

        }

        int ans = dijistra(s, e);

        printf("%d\n", ans < MAX ? ans : -1);

    }

    return 0;

}