LYDSY 1854
题目大意
暂无
题目解法
暂无
RTFC
#include <cstdio>
int head[10010], next[2000010], to[2000010], ecnt, ts;
int vis[1000010], pre[1000010];
inline void addEdge(int f, int t)
{
ecnt++;
next[ecnt] = head[f];
head[f] = ecnt;
to[ecnt] = t;
}
bool dfs(int u)
{
for (int cur = head[u], v; cur; cur = next[cur])
if (vis[to[cur]] != ts)
{
v = to[cur], vis[v] = ts;
if (!pre[v] || dfs(pre[v]))
{
pre[v] = u;
return true;
}
}
return false;
}
int main()
{
int n;
scanf("%d", &n);
for (int i = 1, x, y; i <= n; i++)
{
scanf("%d%d", &x, &y);
addEdge(x, i);
addEdge(y, i);
}
for (ts = 1; ts <= 10001; ts++)
if (!dfs(ts)) break;
printf("%d", ts - 1);
return 0;
}