?????????http://poj.org/problem?id=1325
???????????????????????????????????????????????????
???????????????????????????????????????????????????????????????????????????????????????????????????
??????????????????????????????ans=0??????WA???????????????????????????????????????????????????A??????????????????
??????1?????????
#include<iostream> #include<cstdio> #include<cstring> using namespace std; int n,m,k,pre1[305],pre2[305],head[305],ct,ans; bool vis[305]; struct N{ int to,next; }edge[3005]; void add(int x,int y) { ct++; edge[ct].to=y; edge[ct].next=head[x]; head[x]=ct; } bool dfs(int b) { for(int i=head[b];i;i=edge[i].next) { int a=edge[i].to; if(vis[a])continue; vis[a]=1; if(!pre1[a]||dfs(pre1[a])) { pre1[a]=b; pre2[b]=a; return 1; } } return 0; } bool dfs2(int b) { vis[b]=1; for(int i=head[b];i;i=edge[i].next) { int a=edge[i].to; if(vis[a])continue; vis[a]=1; if(!pre1[a]||dfs2(pre1[a])) { pre1[a]=b; pre2[b]=a; return 1; } } return 0; } int main() { while(1) { ct=0;ans=0;//! memset(pre1,0,sizeof pre1); memset(pre2,0,sizeof pre2); memset(head,0,sizeof head); scanf("%d",&n); if(!n)return 0; scanf("%d%d",&m,&k); int d,a,b; for(int i=1;i<=k;i++) { scanf("%d%d%d",&d,&a,&b); if(a*b==0)continue; add(a+100,b); add(b,a+100); } for(int i=1;i<m;i++)//???????????? if(!pre2[i]) { memset(vis,0,sizeof vis); vis[i]=1;// dfs(i); } memset(vis,0,sizeof vis); for(int i=1;i<m;i++) if(!pre2[i]) dfs2(i); for(int i=1;i<m;i++) if(!vis[i])ans++; for(int i=101;i<n+100;i++) if(vis[i])ans++; printf("%d\n",ans); } }
??????2?????????
#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int n,m,k,pre[305],head[305],ct,ans;
bool vis[305];
struct N{
int to,next;
}edge[3005];
void add(int x,int y)
{
ct++;
edge[ct].to=y;
edge[ct].next=head[x];
head[x]=ct;
}
bool dfs(int b)
{
vis[b]=1;
for(int i=head[b];i;i=edge[i].next)
{
int a=edge[i].to;
if(vis[a])continue;
vis[a]=1;
if(!pre[a]||dfs(pre[a]))
{
pre[a]=b;
pre[b]=a;
return 1;
}
}
return 0;
}
int main()
{
while(1)
{
ct=0;ans=0;//
memset(pre,0,sizeof pre);
memset(head,0,sizeof head);
scanf("%d",&n);
if(!n)return 0;
scanf("%d%d",&m,&k);
int d,a,b;
for(int i=1;i<=k;i++)
{
scanf("%d%d%d",&d,&a,&b);
if(a*b==0)continue;
add(a+100,b);
add(b,a+100);
}
for(int i=1;i<m;i++)//????????????
if(!pre[i])
{
memset(vis,0,sizeof vis);
if(dfs(i))ans++;
}
printf("%d\n",ans);
}
}
??????