Submission #341604

#	Time	Username	Problem	Language	Result	Execution time	Memory
341604		amunduzbaev	Marriage questions (IZhO14_marriage)	C++14	100 / 100	852 ms	25708 KiB

marriage

/** made by amunduzbaev **/
 
#include <bits/stdc++.h>
using namespace std;
 
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define ub upper_bound
#define lb lower_bound
#define ll long long
#define ld long double
#define pii pair<int, int>
#define pll pair<ll, ll>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(),x.rend()
#define fastios ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define vll vector<ll>
#define vii vector<int>
#define vpii vector<pii>
#define vpll vector<pll>
#define cnt(a)__builtin_popcount(a)
template<class T> bool umin(T& a, const T& b) {return a > b? a = b, true:false;}
template<class T> bool umax(T& a, const T& b) {return a < b? a = b, true:false;}
 
const int N = 1e6+5;
const int mod = 1e9+7;
const ll inf = 1e18;
const ld Pi = acos(-1);

int n, m, k, ans, match[N], used[N], ver, l, r;

vector<vii> edges(N);

bool kun(int cur){
	if(used[cur] == ver) return 0;
	used[cur] = ver;
	for(auto x:edges[cur]){
		if(x <= r && x >= l && (match[x] == -1 || kun(match[x]))) { match[x] = cur; return 1; }
	}return 0;
}

void solve(){
	cin>>n>>m>>k;
	for(int i=0;i<k;i++){
		int a, b;
		cin>>a>>b;
		edges[--b].pb(--a);
	}
	
	for(int i=0;i<n;i++) match[i] = -1;
	
	vii need;
	for(int i=0;i<m;i++){
		int cur = i;
		ver++;
		while(r < n && !kun(cur)) r++, ver++;
		if(r == n) {
			cout<<0<<endl;
			return;
		}
		//for(int i=0;i<n;i++) cout<<match[i]<<" ";
		//cout<<"\n";
	}
	
	bool ok = 1;
	for(l=0;l<n && ok;l++){
		while(!need.empty()){
			int cur = need.back();
			ver++;
			while(r < n && !kun(cur)) r++, ver++;
			if(r == n) { ok = 0; break; }
			need.pop_back();
		}
		if(!ok) break;
		//cout<<l<<" "<<r<<"\n";
		ans += (n-r);
		if(match[l] != -1){
			need.pb(match[l]);
			match[l] = -1;
		}
	}
	cout<<ans<<"\n";
	return;
}


main(){
	fastios
	int t = 0;
	if(!t) solve();
	else {
		cin>>t;
		while (t--) solve();
	}
}

Compilation message (stderr)

marriage.cpp:90:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   90 | main(){
      |      ^

• Subtask 1: 100 / 100