mmp图真难呀
Floyd
#include <cstdio>
int main(){
int e[10][10],k,i,j,n,m,t1,t2,t3;
int inf=99999999; //用inf(infinity的缩写)存储一个我们认为的正无穷值
//读入n和m,n表示顶点个数,m表示边的条数
scanf("%d %d",&n,&m);
//初始化
for(i=1;i<=n;i++)
for(j=1;j<=n;j++)
if(i==j) e[i][j]=0;
else e[i][j]=inf;
//读入边
for(i=1;i<=m;i++)
{
scanf("%d%d%d",&t1,&t2,&t3);
e[t1][t2]=t3;
}
//核心语句
for(k=1;k<=n;k++)
for(i=1;i<=n;i++)
for(j=1;j<=n;j++)
if(e[i][j]>e[i][k]+e[k][j] )
e[i][j]=e[i][k]+e[k][j];
//输出最终的结果
for(i=1;i<=n;i++)
{
for(j=1;j<=n;j++)
{
printf("%10d",e[i][j]);
}
printf("\n");
}
return 0;
}
Dijkstra
const int INF=0x3f3f3f3f;
const int maxn=1200;
int dist[maxn],g[maxn][maxn],N;
bool vis[maxn];
void dijkstra()
{
for(int i=1;i<=N;i++)
dist[i]=(i==1)?0:INF;
memset(vis,0,sizeof(vis));
for(int i=1;i<=N;i++)
{
int mark=-1,mindis=INF;
for(int j=1;j<=N;j++)
{
if(!vis[j]&&dist[j]<mindis)
{
mindis=dist[j];
mark=j;
}
}
vis[mark]=1;
for(int j=1;j<=N;j++)
{
if(!vis[j])
{
dist[j]=min(dist[j],dist[mark]+g[mark][j]);
}
}
}
}
SPFA
#include "bits/stdc++.h"
using namespace std;
const int maxN = 200010 ;
struct Edge
{
int to , next , w ;
} e[ maxN ];
int n,m,cnt,p[ maxN ],Dis[ maxN ];
int In[maxN ];
bool visited[ maxN ];
void Add_Edge ( const int x , const int y , const int z )
{
e[ ++cnt ] . to = y ;
e[ cnt ] . next = p[ x ];
e[ cnt ] . w = z ;
p[ x ] = cnt ;
return ;
}
bool Spfa(const int S)
{
int i,t,temp;
queue<int> Q;
memset ( visited , 0 , sizeof ( visited ) ) ;
memset ( Dis , 0x3f , sizeof ( Dis ) ) ;
memset ( In , 0 , sizeof ( In ) ) ;
Q.push ( S ) ;
visited [ S ] = true ;
Dis [ S ] = 0 ;
while( !Q.empty ( ) )
{
t = Q.front ( ) ;Q.pop ( ) ;visited [ t ] = false ;
for( i=p[t] ; i ; i = e[ i ].next )
{
temp = e[ i ].to ;
if( Dis[ temp ] > Dis[ t ] + e[ i ].w )
{
Dis[ temp ] =Dis[ t ] + e[ i ].w ;
if( !visited[ temp ] )
{
Q.push(temp);
visited[temp]=true;
if(++In[temp]>n)return false;
}
}
}
}
return true;
}
int main ( )
{
int S , T ;
scanf ( "%d%d%d%d" , &n , &m , &S , &T ) ;
for(int i=1 ; i<=m ; ++i )
{
int x , y , _ ;
scanf ( "%d%d%d" , &x , &y , &_ ) ;
Add_Edge ( x , y , _ ) ;
}
if ( !Spfa ( S ) ) printf ( "FAIL!\n" ) ;
else printf ( "%d\n" , Dis[ T ] ) ;
return 0;
}
代码来源 懒得看懒得敲的我