Submission #905041

#	Time	Username	Problem	Language	Result	Execution time	Memory
905041		khachatur25	Marriage questions (IZhO14_marriage)	C++14	100 / 100	334 ms	3412 KiB

marriage

#include <bits/stdc++.h>
using namespace std;

const int N = 50005;

int n,m,k;
vector<int>g[N];

bool used[N];
int mt[N];

bool kuhn(int v,int L,int R){
    if(used[v])return false;
    used[v] = true;
    for(int i = 0;i < (int)g[v].size();i++){
        int to = g[v][i];
        if(to < L)continue;
        if(to > R)break;
        if(mt[to] == -1 || kuhn(mt[to],L,R)){
            mt[to] = v;
            return true;
        }
    }
    return false;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin.tie(NULL);
    cin >> n >> m >> k;
    for(int i = 1;i <= k;i++){
        //scanf("%d""%d",&a,&b);
        int a,b;
        cin >> a >> b;
        a += m;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    
    for(int i = 1;i <= m;i++){
        sort(g[i].begin(),g[i].end());
    }
    int ina = m, inb = n, idx = -1;
    while(ina <= inb){
        int mid = (ina + inb) >> 1;
        for(int i = 1;i <= mid;i++){
            mt[i + m] = -1;
        }
        int cnt = 0;
        for(int i = 1;i <= m;i++){
            for(int j = 1;j <= m;j++){
                used[j] = false;
            }
            bool f = kuhn(i,1,mid + m);
            if(f)cnt++;
        }
        if(cnt == m){
            idx = mid;
            inb = mid - 1;
        }
        else{
            ina = mid + 1;
        }
    }
    if(idx == -1){
        cout << 0;
        return 0;
    }
    for(int i = 1;i <= n;i++){
        mt[i + m] = -1;
    }
    for(int i = 1;i <= m;i++){
        for(int j = 1;j <= m;j++){
            used[j] = false;
        }
        kuhn(i,1,idx + m);
    }
    int ans = n - idx + 1;
    for(int i = 1;i <= n;i++){
        if(mt[i + m] == -1){
            ans += n - idx + 1;
            continue;
        }
        int girl = mt[i + m];
        while(idx <= n){
            for(int j = 1;j <= m;j++){
                used[j] = false;
            }
            bool f = kuhn(girl,i + 1 + m,idx + m);
            if(f)break;
            idx++;
        }
        if(idx == n + 1)break;
        ans += n - idx + 1;
    }
    cout << ans;
}

• Subtask 1: 100 / 100