最短路径之 Dijkstra模板

一：时间复杂度为O(V*V)的Dijkstra

const int Max_v = 100 + 10;
const int INF = 1<<30;
int cost[Max_v][Max_v];//权值
int d[Max_v];//顶点ｓ出发最短距离
bool used[Max_v];//以使用过的图
int V;//顶点数
int Edge;//边数

void dijkstra(int s)
{

    fill(d,d+V,INF);
    fill(used,used+V,false);
    d[s]  = 0;
    while(true)
    {
        int v = -1;
        for(int u = 0; u<V; u++)
        {
            if(!used[u] && (v == -1 || d[u] < d[v]))  v = u;
        }
        if(v == -1) break;
        used[v] = true;
        for(int u = 0; u <V; u++)
        {
            d[u] = min(d[u],d[v] + cost[v][u]);
        }
    }
  printf("%d\n",d[V-1]);
}

const int maxn = 1000 + 10;
const int INF = 1<<30;
typedef pair<int, int> P;
int N, R;
struct edge
{
    int to, cost;
};
vector<edge> G[maxn];
int d[maxn];  //最短路径

void solve()
{
    priority_queue<P, vector<P>, greater<P> > que;
    fill(d, d+N, INF);  //最短距离

    d[0] = 0;
    que.push(P(0,0));
    while(!que.empty())
    {
        P p = que.top();
        que.pop();
        int v = p.second;
        if(d[v] < p.first) continue;
        for(int i=0; i<G[v].size(); ++i)
        {
            edge e = G[v][i];
            if(d[e.to] > d[v] + e.cost)
            {
                d[e.to] = d[v] + e.cost;
                que.push(P(d[e.to],e.to));
            }

        }
    }
    printf("%d\n",d[N-1]);
}

 2 1
1 2 3
3 3
1 2 5
2 3 5
3 1 2
0 0 

 3
2 

第一种AC代码

#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;

const int Max_v = 100 + 10;
const int INF = 1<<30;
int cost[Max_v][Max_v];//权值
int d[Max_v];//顶点ｓ出发最短距离
bool used[Max_v];//以使用过的图
int V;//顶点数
int Edge;//边数

void dijkstra(int s)
{

    fill(d,d+V,INF);
    fill(used,used+V,false);
    d[s]  = 0;
    while(true)
    {
        int v = -1;
        for(int u = 0; u<V; u++)
        {
            if(!used[u] && (v == -1 || d[u] < d[v]))  v = u;
        }
        if(v == -1) break;
        used[v] = true;
        for(int u = 0; u <V; u++)
        {
            d[u] = min(d[u],d[v] + cost[v][u]);
        }
    }
  printf("%d\n",d[V-1]);
}
int main()
{
#ifdef xxz
    freopen("in.txt","r",stdin);
#endif // xxz
    int Case;
    while(scanf("%d%d",&V,&Edge) != EOF)
    {
        if(V == 0 && Edge == 0) break;
        for(int i = 0; i < Max_v; i++) fill(cost[i],cost[i]+Max_v,INF);//注意每次都要初始化权值，否则WA
        for(int i = 0 ; i < Edge; i++)
        {
            int u,v,value;
            scanf("%d%d%d",&u,&v,&value);
            u--,v--;
            cost[u][v] = cost[v][u] = value;
        }
       dijkstra(0);
    }
    return 0;
}

#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;

const int maxn = 1000 + 10;
const int INF = 1<<30;
typedef pair<int, int> P;
int N, R;
struct edge
{
    int to, cost;
};
vector<edge> G[maxn];
int d[maxn];  //最短路径

void solve()
{
    priority_queue<P, vector<P>, greater<P> > que;
    fill(d, d+N, INF);  //最短距离

    d[0] = 0;
    que.push(P(0,0));
    while(!que.empty())
    {
        P p = que.top();
        que.pop();
        int v = p.second;
        if(d[v] < p.first) continue;
        for(int i=0; i<G[v].size(); ++i)
        {
            edge e = G[v][i];
            if(d[e.to] > d[v] + e.cost)
            {
                d[e.to] = d[v] + e.cost;
                que.push(P(d[e.to],e.to));
            }

        }
    }
    printf("%d\n",d[N-1]);
}

int main()
{
    int i, a, b, c;
    edge e;
    while(~scanf("%d%d",&N,&R))
    {
        if(N == 0 && R == 0) break;
        for(i = 0; i < maxn; i++) G[i].clear();

        for(i=0; i<R; ++i)
        {
            scanf("%d%d%d", &a, &b, &c);
            a--,b--;
            e.to = b, e.cost = c;
            G[a].push_back(e);
            e.to = a;
            G[b].push_back(e);
        }
        solve();
    }
    return 0;
}

最短路径之 Dijkstra模板

原文：http://blog.csdn.net/u013445530/article/details/43711873