HDU 2544（简单最短路）

/*
使用pair代替结构
*/

#include <iostream>
#include <cstdio>
#include <queue>
#include <vector>
using namespace std;
const int Ni = 10000;
const int INF = 1<<27;

typedef pair<int,int> pa;

int dis[Ni],n;//dis使用1-n的部分

vector<pair<int,int> > eg[Ni];

void Dijkstra(int s)
{
int i,j;
for(i=0;i<=n;i++)//要到n
dis[i] = INF;
priority_queue<pa> q;  //优先级队列：小顶堆
dis[s] = 0;
q.push(make_pair(s,dis[s]));

while(!q.empty())
{
pa x = q.top();
q.pop();
int w = x.first;
for(j = 0;j<eg[w].size();j++)//遍历x的所有邻接点
{
pa y = eg[w][j];//y是x的邻接点
int u = y.first;
if(dis[u]>x.second+y.second)
{
dis[u] = x.second+y.second;
q.push(make_pair(u,dis[u]));
}
}
}

}

int main()
{
int m,a,b,d;//关系个数
while(cin>>n>>m,m+n)
{
for(int i = 0;i<=n;i++)
eg[i].clear();//初始化
while(m--)
{
cin>>a>>b>>d;
eg[a].push_back(make_pair(b,d));
eg[b].push_back(make_pair(a,d));
}

Dijkstra(1);
if(dis
!=INF)
cout<<dis
<<endl;
else
cout<<"-1\n";
}

return 0;
}

#include <cstdio>
using namespace std;
const int L = 1010;
const int INF = 1<<27;

int map[L][L];
int vis[L];
int dis[L];

int n,m;

void Dijkstra(int s)
{
int i,j,k;
int min;
for(i = 0;i<=n;i++)
{
dis[i] = map[s][i];
vis[i] = 0;
}

vis[s] = 1;
dis[s] = 0;

for(i = 0;i<=n;i++)
{
min = INF;
for(j = 0;j<=n;j++)
{
if(dis[j]<min && !vis[j])
{
k = j;
min = dis[j];
}
}

vis[k] = 1;

for(j = 0;j<=n;j++)
{
if(dis[j] > min+map[k][j] && !vis[j])
{
dis[j] = min+map[k][j];
}
}
}
}

void init()
{
int i,j;
for(i = 0;i<=n;i++)
{
map[i][i] = 0;
for(j = i+1;j<=n;j++)
{
map[i][j] = map[j][i] = INF;
}
}

while(m--)
{
int a,b,w;
scanf("%d%d%d",&a,&b,&w);
if(w<map[a][b])//可能有同两点，但不同weight
{
map[a][b] = w;
map[b][a] = w;
}
}
}

int main()
{
while(scanf("%d%d",&n,&m),n+m)
{
int r,t;

init();

Dijkstra(1);

if(dis
!=INF)
printf("%d\n",dis
);
else
printf("-1\n");

}

return 0;
}