poj1122 FDNY to the Rescue! 最短路

  这道题是最短路问题，开始卡了好久后来才发现是因为i,j坐标输入有问题。我更改了i,j坐标顺序才发现正确结果，坑啊！

  不过别的就是个裸地最短路了。

#include <iostream>
#include <stdio.h>
#include <cstring>
#include <algorithm>
#define INF 100000000
#define maxn 25
using namespace std;
int n;
int edge[maxn][maxn];
int dist[maxn];
int s[maxn];
int path[maxn];
struct point
{
    int num,len;
}points[maxn];
bool cmp(point a,point b)
{
    return a.len<b.len;
}
void dijkstra(int v0)
{
    int i,j,k;
    for(i=0;i<n;++i)
    {
        dist[i]=edge[v0][i];    s[i]=0;
        if(i!=v0&&dist[i]<INF)    path[i]=v0;
        else path[i]=1;
    }
    s[v0]=1;    dist[v0]=0;
    for(i=0;i<n-1;++i)
    {
        int min=INF,u=v0;
        for(j=0;j<n;++j)
        {
            if(!s[j]&&dist[j]<min)
            {
                u=j;    min=dist[j];
            }
        }
        s[u]=1;
        for(k=0;k<n;++k)
        {
            if(!s[k]&&edge[u][k]<INF&&dist[u]+edge[u][k]<dist[k])
            {
                dist[k]=dist[u]+edge[u][k];    path[k]=u;
            }
        }
    }
}
int main()
{
    int i,j;
    cin>>n;
    for(i=0;i<n;++i)
        for(j=0;j<n;++j)
        {
            cin>>edge[j][i];
            if(edge[j][i]==-1) edge[j][i]=INF;
        }
    int begin,temp,count=0;
    cin>>begin;
    begin--;
    dijkstra(begin);
    while(cin>>temp)
    {
        if(temp==-2) break;
        points[count++].num=temp-1;
    }    
    for(i=0;i<count;++i)
        points[i].len=dist[points[i].num];
    sort(points,points+count,cmp);
    int shortest[maxn];
    cout<<"Org\tDest\tTime\tPath"<<endl;
    for(i=0;i<count;++i)
    {
        cout<<points[i].num+1<<"\t"<<begin+1<<"\t"<<points[i].len;
        memset(shortest,0,sizeof(shortest));
        int k=0;
        shortest[k]=points[i].num;

        while(path[shortest[k]]!=begin)
        {
            ++k;shortest[k]=path[shortest[k-1]];
        }
        k++;    shortest[k]=begin;
        if(shortest[k]==shortest[0]) cout<<"\t"<<shortest[k]+1;
        else
        for(j=0;j<=k;j++)
            cout<<"\t"<<shortest[j]+1;
        cout<<endl;
    }

    return 0;

}