Dijkstra算法之三

#include <iostream>        //poj 1502 MPI Maelstrom
#include<string>
using namespace std;                                
const int MaxWeight=INT_MAX;            //MaxWeight表示无穷大
int Vertex,edge[102][102],distD[102],i,j;
void init()
{
    cin>>Vertex;
    for(i=1;i<=Vertex;i++)
        for(j=1;j<=Vertex;j++)
        {
            if(i==j)
                edge[i][j]=0;
            else
                edge[i][j]=MaxWeight;
        }
    string p;
    for(int i=2;i<=Vertex;++i)
        for(int j=1;j<i;++j)
        {
            cin>>p;
            if(p!="x")
            {
                int d=0;
                for(int k=0;k<p.size();++k)
                    d=10*d+(p[k]-'0');
                edge[j][i]=edge[i][j]=d;
            }
        }
}
void ShortestPath_Dijstra(int v)     //从源点v到其余各顶点的最短路径长度
{
    int i,min,u,j,S[102],pathD[102];    
    for(i=1;i<=Vertex;i++)
    {
        distD[i]=edge[v][i];S[i]=0;
        if(i!=v&&distD[i]<MaxWeight)
            pathD[i]=v;
        else
            pathD[i]=-1;
    }
    S[v]=1;
    for(i=1;i<Vertex;i++)    
    {
        min=MaxWeight;
        for(j=1;j<=Vertex;j++)
            if(!S[j]&&distD[j]<min)
            {
                u=j;min=distD[j];
            }
        S[u]=1;
        for(j=1;j<=Vertex;j++)
            if(!S[j]&&(long long)distD[u]+edge[u][j]<(long long)distD[j])
            {
                distD[j]=distD[u]+edge[u][j];pathD[j]=u;
            }
    }
}
int main()
{
    init();
    ShortestPath_Dijstra(1);
    int mx=0;
    for(i=1;i<=Vertex;i++)
        mx=max(mx,distD[i]);
    cout<<mx<<endl;
}