Submission #39136

#	Time	Username	Problem	Language	Result	Execution time	Memory
39136		RockyB	Marriage questions (IZhO14_marriage)	C++14	82 / 100	1500 ms	3832 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)32000 + 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, tmr1;
int p[N];

int was[N], good[N];
int dfs(int v, int L, int R) {
	if (was[v] == tmr) return 0;
	was[v] = tmr;
	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;
}
int ok(int L, int R) {
	L += m, R += m;
	memset(p, -1, sizeof(p));
	++tmr;
	++tmr1;
	int cnt = 0, last = inf;
	for (int i = m; i >= 1; i--) {
		for (auto to : g[i]) {
			if (p[to] == -1 && L <= to && to <= R) {
				p[to] = i;
				good[i] = tmr1;
				last = min(last, to - m);
				++cnt;
				break;
			}
		}
	}
	if (cnt == m) return last;
	for (int i = 1; i <= m; i++) {
		if (good[i] == tmr1) continue;
		++tmr;
		int now = cnt;
		cnt += dfs(i, L, R);
	}
	if (cnt == m) {
		for (int i = m + 1; i <= n + m; i++) {
			if (p[i] != -1) {
				return i - m;
			}
		}
	}
	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]), greater <int> ());
	}
	int ans = 0, l = 1;
	for (int i = 1; i <= n; i++) {
		while (1) {
			int nxt = ok(l, i);
			if (!nxt) break;
			l = nxt + 1;
		}
		ans += l - 1;
	}
	cout << ans;
	ioi
}

Compilation message (stderr)

marriage.cpp: In function 'int ok(int, int)':
marriage.cpp:74:7: warning: unused variable 'now' [-Wunused-variable]
   int now = cnt;
       ^

• Subtask 1: 82 / 100