poj 1273 Drainage Ditches

#include<stdio.h>
#define MAX 0x3f3f3f3f
#define min(x,y) ((x<y)?(x):(y))
int map[300][300];
int dis[300];
int q[2000],h,r;
int N,M,ANS;
int BFS(void)
{
int i,j;
memset(dis,0xff,sizeof(dis));
dis[1]=0;
h=0;r=1;
q[1]=1;
while(h<r)
{
j=q[++h];
for(i=1;i<=N;i++)
{
if(dis[i]<0&&map[j][i]>0)
{
dis[i]=dis[j]+1;
q[++r]=i;
}
}
}
if(dis
>0)
return 1;
else
return 0;

}
int find(int x,int low)
{
int i,a=0;
if(x==N)
return low;
for(i=1;i<=N;i++)
{
if(map[x][i]>0&&dis[i]==dis[x]+1&&(a=find(i,min(low,map[x][i]))))
{
map[x][i]-=a;
map[i][x]+=a;
return a;
}
}
return 0;
}
int main(void)
{
int i,f,t,flow,tans;
while(~scanf("%d%d",&M,&N))
{
memset(map,0,sizeof(map));
for(i=1;i<=M;i++)
{
scanf("%d%d%d",&f,&t,&flow);
map[f][t]+=flow;
}
ANS=0;
while(BFS())
{
while(tans=find(1,0x3f3f3f3f))
ANS+=tans;
}
printf("%d\n",ANS);
}
}

#include<iostream>
#include<queue>
using namespace std;
#define INF 0x3f3f3f3f
#define N 210
#define min(x,y) ((x>y)?(y):(x))
int map

;
bool vis
;
int pre
;
int m,n;
bool bfs(int s,int t)
{
int p;
queue<int>q;
memset(pre,-1,sizeof(pre));
memset(vis,false,sizeof(vis));
pre[s]=s;
vis[s]=true;
q.push(s);
while(!q.empty())
{
p=q.front();
q.pop();
for(int i=1;i<=n;i++)
{
if(map[p][i]>0&&!vis[i])
{
pre[i]=p;
vis[i]=true;
if(i==t)
return true;
q.push(i);
}
}
}
return false;
}
int EdmondsKarp(int s,int t)
{
int flow=0,d,i;
while(bfs(s,t))
{
d=INF;
for(i=t;i!=s;i=pre[i])
d=min(d,map[pre[i]][i]);
for(i=t;i!=s;i=pre[i])
{
map[pre[i]][i]-=d;
map[i][pre[i]]+=d;
}
flow+=d;
}
return flow;
}
int main(void)
{
while(~scanf("%d%d",&m,&n))
{
int u,v,w;
memset(map,0,sizeof(map));
for(int i=0;i<m;i++)
{
scanf("%d%d%d",&u,&v,&w);
map[u][v]+=w;
}
printf("%d\n",EdmondsKarp(1,n));
}
}