Submission #1216462

#	Time	Username	Problem	Language	Result	Execution time	Memory
1216462		steveonalex	Hiring (IOI09_hiring)	C++20	94 / 100	615 ms	68000 KiB

hiring

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(abs(a), abs(b));}
ll lcm(ll a, ll b){return abs(a) / gcd(a, b) * abs(b);}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ull mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }

template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }


struct FenwickTree{
    int n;
    vector<ll> a;

    FenwickTree(int _n){
        n = _n;
        a.resize(n+1);
    }

    void update(int i, ll v){
        while(i <= n){
            a[i] += v;
            i += LASTBIT(i);
        }
    }

    ll get(int i){
        ll ans = 0;
        while(i > 0){
            ans += a[i];
            i -= LASTBIT(i);
        }
        return ans;
    }

    ll get(int l, int r){return get(r) - get(l-1);}

    int binary_lift(ll x){
        int p = MASK(logOf(n)), idx =0;
        while(p > 0){
            if (idx + p <= n && x >= a[idx + p]){
                idx += p;
                x -= a[idx];
            }
            p >>= 1;
        }
        return idx;
    }
};

ostream& operator << (ostream &os, pair<ll, ll> x){
    os << "(" << x.first << ", " << x.second << ")";
    return os;
}

void solve(){
    int n; cin >> n;
    ll w; cin >> w;

    vector<pair<ll, ll>> a(n);
    for(int i = 0; i < n; ++i) cin >> a[i].first >> a[i].second;

    map<pair<int, int>, vector<int>> mp_idx;
    for(int i= 0; i < n; ++i) mp_idx[a[i]].push_back(i);

    sort(ALL(a), [](pair<ll, ll> x, pair<ll, ll> y){
        return x.first * y.second < y.first * x.second;
    });

    vector<pair<ll, ll>> val;
    for(int i = 0; i < n; ++i) val.push_back(make_pair(a[i].second, i));

    sort(ALL(val));

    FenwickTree bit(n), sum(n);

    int optimal_idx = 0;
    int best_cnt = 0;
    pair<ll, ll> best_val = make_pair(1, 0);
    for(int i = 0; i < n; ++i){
        pair<ll, ll> cur = make_pair(a[i].second, i);
        int idx = lower_bound(ALL(val), cur) - val.begin() + 1;
        bit.update(idx, 1);
        sum.update(idx, a[i].second);

        ll afford = w * a[i].second / a[i].first;
        idx = sum.binary_lift(afford);

        int cnt = bit.get(idx);
        ll s = sum.get(idx);
        pair<ll, ll> cur_val = make_pair(s * a[i].first, a[i].second);;
        if (maximize(best_cnt, cnt)){
            optimal_idx = i;
            best_val = cur_val;
        }
        else if (best_cnt == cnt){
            if (best_val.first * cur_val.second > cur_val.first * best_val.second){
                optimal_idx = i;
                best_val = cur_val;
            }
        }
    }

    vector<int> ans;
    for(int i = 0; i < n; ++i) if ((int) ans.size() < best_cnt){
        if (val[i].second <= optimal_idx){
            pair<ll, ll> cur = a[val[i].second];
            int idx = mp_idx[cur].back(); mp_idx[cur].pop_back();
            ans.push_back(idx + 1);
        }
    }

    cout << ans.size() << "\n";
    sort(ALL(ans));
    printArr(ans, "\n", "");
}
 
int main(void){
    ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
 
    clock_t start = clock();
    
    solve();
    cerr << "Time elapsed: " << clock() - start << "ms!\n";
    return 0;
}

• Subtask 1: 30 / 30
• Subtask 2: 28 / 28
• Subtask 3: 6 / 6
• Subtask 4: 6 / 6
• Subtask 5: 6 / 6
• Subtask 6: 6 / 6
• Subtask 7: 6 / 6
• Subtask 8: 6 / 6
• Subtask 9: 0 / 6