Submission #38995

#	Time	Username	Problem	Language	Result	Execution time	Memory
38995		RockyB	Marriage questions (IZhO14_marriage)	C++14	46 / 100	1500 ms	3584 KiB

marriage

/// In The Name Of God
 
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,sse3,sse4,popcnt,abm,mmx")
 
#include <bits/stdc++.h>
 
#define f first
#define s second
 
#define pb push_back
#define pp pop_back
#define mp make_pair
 
#define sz(x) (int)x.size()
#define sqr(x) ((x) * 1ll * (x))
#define all(x) x.begin(), x.end()
 
#define Kazakhstan ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);
 
#define nl '\n'
#define ioi exit(0);
 
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
 
const int N = (int)3e4 + 7, inf = (int)1e9 + 7, mod = (int)1e9 + 7;
const ll linf = (ll)1e18 + 7;
const int dx[] = {-1, 0, 1, 0, 1, -1, -1, 1}, dy[] = {0, 1, 0, -1, 1, -1, 1, -1};
 
using namespace std;
 
int n, m, k;
vector <int> g[N];
 
int tmr;
int p[N];

bool was[N];
 
int dfs(int v, int L, int R) {
	if (was[v]) return 0;
	was[v] = 1;
	for (auto to : g[v]) {
		if (!(L <= to && to <= R)) continue; 
		if (p[to] == -1 || dfs(p[to], L, R)) {
			p[to] = v;
			return 1;
		}
	}
	return 0;
}
bool good[N];
int ok(int L, int R) {
	L += m, R += m;
	memset(p, -1, sizeof(p));
	memset(was, 0, sizeof(was));
	memset(good, 0, sizeof(good));
	for (int i = 1; i <= m; i++) {
		for (auto to : g[i]) {
			if (p[to] == -1 && L <= to && to <= R) {
				p[to] = i;
				good[i] = 1;
				break;
			}
		}
	}
	for (int i = 1; i <= m; i++) {
		if (good[i]) continue;
		memset(was, 0, sizeof(was));
		dfs(i, L, R);
	}
	int cnt = 0;
	for (int j = m + 1; j <= n + m; j++) {
		cnt += p[j] != -1;
		//cerr << p[j] << nl;
	}
	if (cnt == m) return 1;
	return 0;
}
int main() {
	#ifdef IOI2018
		freopen ("in.txt", "r", stdin);
	#endif
	Kazakhstan
	cin >> n >> m >> k;
	for (int i = 1; i <= k; i++) {
		int a, b;
		cin >> b >> a;
		g[a].pb(b + m);
	}
	for (int i =1 ; i <= m; i++) {
		sort(all(g[i]));
	}
	int ans = 0;
	for (int i = 1; i <= m; i++) {
		int l = i, r = n, res = n + 1;
		while (l <= r) {
			int mid = l + r >> 1;
			if (ok(i, mid)) res = mid, r = mid - 1;
			else l = mid + 1;
		}
		ans += n - res + 1;
	}
	cout << ans;
	ioi
}

Compilation message (stderr)

marriage.cpp: In function 'int main()':
marriage.cpp:100:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    int mid = l + r >> 1;
                ^

• Subtask 1: 46 / 100