uva 10269 最短路

求两次最短路

#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <vector>
#include <sstream>
#include <string>
#include <cstring>
#include <algorithm>
#include <iostream>
#define maxn 105
#define INF 0x7fffffff
#define inf 10000000
#define MOD 1000000007
#define ull unsigned long long
#define ll long long
using namespace std;

int A, B, M, L, K, g[maxn][maxn];
int d[maxn][12];
bool inq[maxn][12];

struct node
{
    int now, s;
    node(int i, int j)
    {
        now = i, s = j;
    }
};

void init()
{
    for(int i = 0; i < maxn; ++ i)
        for(int j = 0; j < maxn; ++ j) g[i][j] = inf;
}

void floyd()
{
    for(int k = 1; k <= A; ++ k)
        for(int i = 1; i <= A+B; ++ i)
            for(int j = 1; j <= A+B; ++ j)
                if(g[i][k] != inf && g[k][j] != inf)
                    g[i][j] = min(g[i][j], g[i][k]+g[k][j]);
}

int spfa()
{
    for(int i = 0; i <= A+B; ++ i)
        for(int j = 0; j <= K; ++ j)
            d[i][j] = inf;
    memset(inq, 0, sizeof(inq));
    queue<node> q;
    d[A+B][0] = 0;
    q.push(node(A+B, 0));
    while(!q.empty())
    {
        node t = q.front();
        q.pop();
        int u = t.now, k = t.s;
        inq[u][k] = false;
        for(int i = 1; i <= A+B; ++ i)
        {
            if(i == u) continue;
            if(k < K && g[u][i] <= L)
            {
                if(d[i][k+1] > d[u][k])
                {
                    d[i][k+1] = d[u][k];
                    if(!inq[i][k+1])
                    {
                        inq[i][k+1] = true;
                        q.push(node(i, k+1));
                    }
                }
            }
            if(d[i][k] > d[u][k]+g[u][i])
            {
                d[i][k] = d[u][k]+g[u][i];
                if(!inq[i][k])
                {
                    inq[i][k] = true;
                    q.push(node(i,k));
                }
            }
        }
    }
    int ans = inf;
    for(int i = 0; i <= K; ++ i) ans = min(ans, d[1][i]);
    return ans;
}

int main()
{
    int t;
    scanf("%d", &t);
    while(t --)
    {
        scanf("%d%d%d%d%d", &A, &B, &M, &L, &K);
        init();
        for(int i = 0; i < M; ++ i)
        {
            int x, y, c;
            scanf("%d%d%d", &x, &y, &c);
            g[x][y] = g[y][x] = c;
        }
        floyd();
        printf("%d\n", spfa());
    }
    return 0;
}


posted @ 2014-03-20 16:18  xlc2845  阅读(106)  评论(0)    收藏  举报