Floyd模板

来源：互联网发布：微信web开发者工具mac 编辑：程序博客网时间：2024/06/16 00:11
#include<cstdio>#include<cstdlib>#include<cstring>#include<iostream>#include<algorithm>using namespace std;#define INF 0x7f#define maxn 200int dis[maxn][maxn];int path[maxn][maxn];int n;void floyd(){    int i,j,k;    for(i=0;i<n;i++)    {        for(j=0;j<n;j++)        {            if(i!=j&&dis[i][j]<INF) path[i][j]=i;            else path[i][j]=-1;        }    }    for(k=0;k<n;k++)    {        for(i=0;i<n;i++)        {            for(j=0;j<n;j++)            {                if(k==i||k==j) continue;                if(dis[i][j]>dis[i][k]+dis[k][j])                {                    dis[i][j]=dis[i][k]+dis[k][j];                    path[i][j]=path[k][j];                }            }        }    }}int main(){    int i,j,from,to,val;    cin>>n;    for(i=0;i<n;i++)    {        for(j=0;j<n;j++)        {            dis[i][j]=INF;        }    }    while(cin>>from>>to>>val)    {        if(from==-1&&to==-1&&val==-1) break;        if(dis[from][to]>val)        dis[from][to]=dis[from][to]=val;    }    floyd();    int shorest[maxn];    for(i=0;i<n;i++)    {        for(j=0;j<n;j++)        {            if(i==j) continue;            printf("%d=>%d\t%d\t",i,j,dis[i][j]);            memset(shorest,0,sizeof(shorest));            int k=0;            shorest[k]=j;            while(path[i][shorest[k]]!=i)            {                k++;                shorest[k]=path[i][shorest[k-1]];            }            k++;            shorest[k]=i;            for(int t=k;t>0;t--)            printf("%d->",shorest[t]);            printf("%d\n",shorest[0]);        }    }    return 0;}
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