hdu1595-find the longest of the shortest

http://acm.hdu.edu.cn/showproblem.php?pid=1595

求最短路中间的最长路径

题意为求最短路，但是要求的是最短路中间当去掉某一条路时的情况下路径最长的，这里是使用Dijkstra写的，代码相较其他简便了很多，值得注意的是当记录路径时，当传入的v0为0 时不要记录

#include<iostream>
#include<cstdio>
#include<cstring>
const int INF = 1000000000 ;
const int maxn = 1005 ;
int edge[ maxn ][ maxn ] ;
int path[ maxn ] ;
int used[ maxn ] ;
int dist[ maxn ] ;
int n , m ;

int Dijkstra( int v0 )
{
int i , j , k ;
memset( used , 0 , sizeof( used ) ) ;
for( i = 0 ; i <= n ; i++ )
{
dist[ i ] = INF ;
}
dist[ 1 ] = 0 ;
for( i = 1 ; i <= n ; i++ )
{
int MIN = INF , u = v0 ;
for( j = 1 ; j <= n ; j++ )
{
if( !used[ j ] && dist[ j ] < MIN )
{
MIN = dist[ j ] ;
u = j ;
}
}
used[ u ] = 1 ;
for( k = 1 ; k <= n ; k++ )
{
if( !used[ k ] && edge[ u ][ k ] && edge[ u ][ k ] + dist[ u ] < dist[ k ] )
{
dist[ k ] = dist[ u ] + edge[ u ][ k ] ;
if( v0 )
path[ k ] = u ;
}
}
}
}

int main()
{
int i , j , k ;
int x , y , temp ;
while( scanf( "%d%d" , &n ,&m ) != EOF )
{
memset( edge , 0 , sizeof( edge ) ) ;
for( i = 1 ; i <= n ; i++ )
{
for( j = 1 ; j <= n ; j++ )
{
if( i == j )
edge[ i ][ j ] = 0 ;
else
edge[ i ][ j ] = INF ;
}
}
memset( path , 0 , sizeof( path ) ) ;
for( i = 0 ; i < m ; i++ )
{
scanf( "%d%d%d" , &x, &y , &temp ) ;
if( temp < edge[ x ][ y ] )
edge[ x ][ y ] = edge[ y ][ x ] = temp ;
}
Dijkstra( 1 ) ;
int MAX = dist[ n ] ;
for( i = n ; i != 1 ; i = path[ i ] )
{
int t = edge[ path[ i ] ][ i ] ;
edge[ path[ i ] ][ i ] = INF ;
edge[ i ][ path[ i ] ] = INF ;
Dijkstra( 0 ) ;

if( dist[ n ] > MAX )
MAX = dist[ n ] ;
edge[ i ][ path[ i ] ] = edge[ path[ i ] ][ i ] = t ;
}
printf( "%d\n" , MAX ) ;
}
return 0 ;
}