Submission #443021

#	Time	Username	Problem	Language	Result	Execution time	Memory
443021		leaked	Marriage questions (IZhO14_marriage)	C++14	20 / 100	151 ms	4676 KiB

marriage

#include <bits/stdc++.h>
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("-O3")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define vec vector
#define sz(x) ( int)x.size()
#define m_p make_pair
#define f first
#define s second
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
using namespace std;
typedef long long ll;
typedef pair<ll, int> pli;
typedef pair<int,ll> pil;
typedef pair<int,int> pii;
typedef unsigned long long ull;
auto rng=bind(uniform_int_distribution<int>(1,1000),mt19937(time(0)));
template<class T> bool umax(T &a,const T &b){return (a<b?a=b,1:0);}
template<class T> bool umin(T &a,const T &b){return (a>b?a=b,1:0);}
const int N=3e4+1;
const int K=165;
const int M=2001;
vec<int> g[M];
vec<int>gr[N];
int uk;
int vl[N];
int mt[N];
int wh[N];
int u[N],tt,n,m;
int tl,tr;
bool kuhn(int v){
    if(u[v]==tt) return 0;
    u[v]=tt;
    for(auto &z : g[v]){
        if(z<=tr && mt[z]==-1){
            mt[z]=v;
            vl[uk++]=v;
            return 1;
        }
    }
    for(auto &z : g[v]){
        if(z<=tr && kuhn(mt[z])){
            mt[z]=v;
            vl[uk++]=v;
            return 1;
        }
    }
    return 0;
}
int check(int l,int r){
    tl=l;tr=r;
    for(int i=0;i<uk;i++){
        mt[vl[i]]=-1;
    }
    uk=0;
    for(int i=0;i<m;i++){
        tt++;
        if(!kuhn(i)) return 0;
    }
    return 1;
}
bool kuhn2(int v){
    if(u[v]==tt) return 0;
    u[v]=tt;
    for(auto &z : gr[v]){
        if(mt[z]==-1){
            mt[z]=v;
            return 1;
        }
    }
    for(auto &z : gr[v]){
        if(kuhn(mt[z])){
            mt[z]=v;
            return 1;
        }
    }
    return 0;
}
signed main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    int k;
    cin>>n>>m>>k;
    for(int i=0;i<k;i++){
        int v,u;
        cin>>v>>u;--v;--u;
        gr[v].pb(u);
    }
    for(int i=0;i<N;i++){
        mt[i]=-1;
        wh[i]=-1;
    }
    int l=n;
    int h=0;
    while(h!=m && l>0){
        l--;
        tt++;
        h+=kuhn2(l);
    }
    if(h!=m){
        cout<<0;
        return 0;
    }
    fill(mt,mt+n,-1);
    for(int i=n-1;i>l;i--){
        for(auto &z : gr[i]) g[z].pb(i);
    }
    int r=n-1;
    ll ans=0;
    for(int i=l;i>=0;i--){
//        cout<<i<<endl;
        for(auto &z : gr[i]) g[z].pb(i);
        while(check(i,r-1)) r--;
//        cout<<i<<' '<<r<<endl;
        ans+=(n-r);
    }
    cout<<ans;
    return 0;
}

/*
5
1 2
2 3
3 4
4 5
5 1
*/

• Subtask 1: 20 / 100