zoj 3088 spfa 最短&最长路径

#include <queue>
#include <vector>
#include <cstdio>
#include<string.h>
#include <iostream>
#include <algorithm>
using namespace std;
typedef long long ll;
int n,m,k;
int down[1010][1010],up[1010][1010];
int distdown[1010],distup[1010];
int pathdown[1010],pathup[1010];
int pathans[2020],id;
inline void read(int &m)
{
int x=0,f=1;char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
m=x*f;
}
void f(int temp)
{
if(pathup[temp]==-1)return;
f(pathup[temp]);
pathans[id++]=temp;
}
void copypath(int i,int j)
{
id=1;
pathans[id++]=i;
f(j);
while(pathdown[j]!=-1)
{
pathans[id++]=pathdown[j];
j=pathdown[j];
}
}
void spfa_down(int k)  //spfa求最长路径
{
bool vis[1010];
memset(vis,0,sizeof(vis));
memset(distdown,0,sizeof(distdown));  //比图的无限小稍微大
queue<int>que;
vis[k]=1;
pathdown[k]=-1;
que.push(k);
while(!que.empty())
{
int v=que.front();
que.pop();
vis[v]=0;
for(int i=1;i<=n;i++)
if(distdown[v]+down[v][i]>distdown[i])
{
distdown[i]=distdown[v]+down[v][i];
pathdown[i]=v;
if(!vis[i])
vis[i]=1,que.push(i);
}
}
}
void spfa_up(int k)  //spfa求最短路径
{
bool vis[1010];
memset(vis,0,sizeof(vis));
for(int i=1;i<=n;i++)
distup[i]=100000000;  //比图的无限大稍微小。不过正常来说令其与图相等，即无限大
vis[k]=1;
distup[k]=0;
pathup[k]=-1;
queue<int>que;
que.push(k);
while(!que.empty())
{
int v=que.front();
que.pop();
vis[v]=0;
for(int i=1;i<=n;i++)
if(distup[v]+up[v][i]<distup[i])
{
distup[i]=distup[v]+up[v][i];
pathup[i]=v;
if(!vis[i])
vis[i]=1,que.push(i);
}
}
}
int main()
{
int cas,a,b,c;
read(cas);
while(cas--)
{
read(n),read(m),read(k);
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++)
up[i][j]=100000000,down[i][j]=-10000000;//将图设为正无限大，负无限大
for(int i=1;i<=m;i++)
{
read(a),read(b),read(c);
down[b][a]=c;//反转
}
for(int i=1;i<=k;i++)
{
read(a),read(b),read(c);
up[a][b]=c;
}
double maxn=0;
for(int i=1;i<=n;i++)
{
spfa_down(i);
spfa_up(i);
for(int j=1;j<=n;j++)
if(i==j)continue;
else if(distdown[j]!=0&&distup[j]!=10000000)
{
double d=1.0*distdown[j]/distup[j];
if(d>maxn)
{
maxn=d;
copypath(i,j);
}
}
}
for(int i=1;i<id;i++)
printf("%d ",pathans[i]);
printf("\n%.3f\n",maxn);
}
return 0;
}