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求指教。。为什么我的代码把maxn .maxm调的很高才能过?maxn = 1000,maxm = 20050 一直RE。
看了discuss,干脆丧心病狂改成很大的了。。然后才过,为什么这题maxn开到1000都不够??费解。。。
#include<cstdio>
#include<cstring>
#include<iostream>
using namespace std;
const int maxn = 100000;
const int maxm = 200500;
const int INF = 0x7FFFFFF;
#define mem(name,value) memset((name),(value),sizeof(name))
struct Side{
int to,next,c;
}side[maxm];
int top,node[maxn];
void add_side(int u,int v,int c,int rc){
side[top]=(Side){v,node[u],c};node[u]=top++;
side[top]=(Side){u,node[v],rc};node[v]=top++;
}
int start,end,cnt,dis[maxn],gap[maxn];
int get_flow(int u,int flow){
//printf("%d %d\n",u,flow);
if(u==end)return flow;
int ans=0;
for(int i=node[u];i!=-1;i=side[i].next){
int v=side[i].to,c=side[i].c;
if(dis[u]>dis[v]&&c){
int f=get_flow(v,min(flow-ans,c));
ans+=f;
side[i].c-=f;
side[i^1].c+=f;
if(ans==flow)return ans;
}
}
if(!(--gap[dis[u]]))dis[start]=cnt+2;
gap[++dis[u]]++;
return ans;
}
int main(){
freopen("input.txt","r",stdin);
int n,np,nc,m;
while(scanf("%d%d%d%d",&n,&np,&nc,&m) != EOF){
top=0;
mem(node,-1);
mem(gap,0);
mem(dis,0);
while(m--){
int u,v,w;
char str[20];
scanf("%s",str);
sscanf(str,"(%d,%d)%d",&u,&v,&w);
//cout<<u<<" "<<v<<" "<<w<<endl;
add_side(u,v,w,0);
}
while(np--)
{
int u = n+1,v,w;
char str[20];
scanf("%s",str);
sscanf(str,"(%d)%d",&v,&w);
//cout<<u<<" "<<v<<" "<<w<<endl;
add_side(u,v,w,0);
}
while(nc--)
{
int u,v = n+2,w;
char str[20];
scanf("%s",str);
sscanf(str,"(%d)%d",&u,&w);
//cout<<u<<" "<<v<<" "<<w<<endl;
add_side(u,v,w,0);
}
if(np==0 || nc==0){cout<<0<<endl; continue;}
int ans=0;
start=n+1;
end=n+2;
cnt=n+2;
gap[0]=cnt;
while(dis[start]<cnt)ans+=get_flow(start,INF);
printf("%d\n",ans);
}
return 0;
}
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