Submission #489448

#	Time	Username	Problem	Language	Result	Execution time	Memory
489448		wiwiho	Remittance (JOI19_remittance)	C++14	0 / 100	1 ms	208 KiB

remittance

#include<bits/stdc++.h>

#define mp make_pair
#define F first
#define S second
#define printv(a, b) { \
    for(auto pv : a) b << pv << " "; \
    b << "\n";\
}

using namespace std;

typedef long long ll;

using pll = pair<ll, ll>;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n;
    cin >> n;

    vector<ll> a(n), b(n);
    ll diff = 0;

    set<pll, greater<>> s;

    auto rmv = [&](int i){
        if(a[i] >= 2 && a[i] - b[i] != 0) s.erase(mp(a[i] - b[i], i));
    };
    auto add = [&](int i){
        if(a[i] >= 2 && a[i] - b[i] != 0) s.insert(mp(a[i] - b[i], i));
    };

    for(int i = 0; i < n; i++){
        cin >> a[i] >> b[i];
        add(i);
        diff += b[i] - a[i];
    }
    //cerr << "diff " << diff << "\n";

    if(diff % 2 || diff > 0){
        cout << "No\n";
        return 0;
    }

    while(!s.empty()){
        pll now = *s.begin();
        int id = now.S;
        s.erase(s.begin());
        //cerr << "test " << now.F << " " << now.S << "\n";

        ll cnt = now.F;
        if(cnt < 0) break;
        cnt = max(cnt / 2, 1LL);
        int nxt = (id + 1) % n;
        //cerr << cnt << " " << nxt << "\n";
        rmv(nxt);
        a[id] -= cnt * 2;
        a[nxt] += cnt;
        add(nxt);
        add(id);
        //printv(a, cerr);
        //printv(b, cerr);
    }

    for(int i = 0; i < n; i++){
        if(a[i] != b[i]){
            cout << "No\n";
            return 0;
        }
    }
    cout << "Yes\n";

    return 0;
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 40
• Subtask 3: 0 / 45