PKU 3692 - Kindergarten (最大团)
题意
幼儿园里女孩全部认识,男孩全部认识,一些女孩和一些男孩认识,要使他们都能认识才能组成一个圈子,求最大圈子人数。
思路
是求最大团,根据公式,就是V - 补图的最大匹配
代码
#include <cstdio>
#include <stack>
#include <set>
#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <functional>
#include <cstring>
#include <algorithm>
#include <cctype>
#include <string>
#include <map>
#include <cmath>
#define LL long long
#define SZ(x) (int)x.size()
#define Lowbit(x) ((x) & (-x))
#define MP(a, b) make_pair(a, b)
#define MS(arr, num) memset(arr, num, sizeof(arr))
#define PB push_back
#define F first
#define S second
#define ROP freopen("input.txt", "r", stdin);
#define MID(a, b) (a + ((b - a) >> 1))
#define LC rt << 1, l, mid
#define RC rt << 1|1, mid + 1, r
#define LRT rt << 1
#define RRT rt << 1|1
#define BitCount(x) __builtin_popcount(x)
const double PI = acos(-1.0);
const int INF = 0x3f3f3f3f;
using namespace std;
const int MAXN = 200 + 10;
const int MOD = 1e9 + 7;
const int dir[][2] = { {-1, 0}, {1, 0}, {0, -1}, {0, 1} };
typedef pair<int, int> pii;
typedef vector<int>::iterator viti;
typedef vector<pii>::iterator vitii;
int mp[MAXN][MAXN], nb;
struct EDGE
{
int from, to;
};
struct BIMATCHING
{
int link[MAXN], head[MAXN], next[MAXN * MAXN];
bool vis[MAXN];
vector<EDGE> edges;
void init()
{
MS(link, -1); MS(head, -1);
edges.clear();
}
void add_edge(int from, int to)
{
edges.PB((EDGE){from, to});
int m = SZ(edges);
next[m - 1] = head[from];
head[from] = m - 1;
}
bool dfs(int u)
{
for (int v = 1; v <= nb; v++)
{
if (!vis[v] && mp[u][v])
{
vis[v] = 1;
if (link[v] == -1 || dfs(link[v]))
{
link[v] = u;
return true;
}
}
}
return false;
}
int solve(int n) //n是待匹配的总数,这里默认从1开始
{
int res = 0;
for (int i = 1; i <= n; i++)
{
MS(vis, 0);
if (dfs(i)) res++;
}
return res;
}
}hun;
int main()
{
//ROP;
int ng, n, i, j, cases = 0;
while (scanf("%d%d%d", &ng, &nb, &n), ng + nb + n)
{
MS(mp, -1);
hun.init();
while (n--)
{
int a, b;
scanf("%d%d", &a, &b);
mp[a][b] = 0;
}
printf("Case %d: %d\n", ++cases, ng + nb - hun.solve(ng));
}
return 0;
}