Winter_coming @ 2018-03-04 19:40:59
我真的不是水帖,,,刚才那个代码成了一坨。。
#include<iostream>
#include<cstdio>
#include<algorithm>
#include<queue>
#include<cstring>
using namespace std;
const int inf=99999999;
const int maxm=100086;
const int maxn=10086;
int next[maxm],head[maxn],to[maxm],w[maxm],n,m,cnt=-1,cur[maxn],dep[maxn],s,t,j,k,l;
inline int HongkongReporter(){
int x=0;char c=getchar();
while (!isdigit(c)){
c=getchar();
}
while (isdigit(c)){
x=(x<<3)+(x<<1)+c-48;
c=getchar();
}return x;
}
inline void add(int x,int y,int z){
to[++cnt]=y;next[cnt]=head[x];head[x]=cnt;w[cnt]=z;
to[++cnt]=x;next[cnt]=head[y];head[y]=cnt;w[cnt]=0;
}
bool bfs(){
queue<int> q;
memset(dep,0,sizeof(dep));
q.push(s);dep[s]=1;
while (!q.empty()){
int u=q.front();q.pop();
for (int i=head[u];i!=-1;i=next[i]){
int v=to[i];
if (w[i]>0&&dep[v]==0){
dep[v]=dep[u]+1;
q.push(v);
}
}
}
if (dep[t])return 1;
else return 0;
}
inline int dfs(int x,int dist){
if (x==t)return dist;
for (int& i=cur[x];i!=-1;i=next[i]){
int v=to[i];
if (dep[x]+1==dep[v]&&w[i]!=0){
int d=dfs(v,min(dist,w[i]));
if (d){
w[i]-=d;
w[i^1]+=d;
return d;
}
}
}
return 0;
}
int dinic(){
int ans=0;
while (bfs()){
for (int i=1;i<=n;i++)cur[i]=head[i];
while (int d=dfs(s,inf))ans+=d;
}
return ans;
}
int main(){
n=HongkongReporter();m=HongkongReporter();s=HongkongReporter();t=HongkongReporter();
memset(head,-1,sizeof(head));
memset(next,-1,sizeof(next));
for (int i=1;i<=m;i++){
j=HongkongReporter();k=HongkongReporter();l=HongkongReporter();
if (j==k)continue;
add(j,k,l);
}
printf("%d",dinic());
return 0;
}
by star_magic_young @ 2018-03-04 19:51:50
你存边的数组开小了,要再开大一倍