Submission #747764

#	Time	Username	Problem	Language	Result	Execution time	Memory
747764		adrilen	Detecting Molecules (IOI16_molecules)	C++17	100 / 100	47 ms	6628 KiB

molecules

#include "molecules.h"
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
typedef pair<int, int> pii;

constexpr int maxn = 2e5 + 5;

ll pref[maxn] = { 0 }, suff[maxn] = { 0 };

std::vector<int> find_subset(int l, int u, std::vector<int> w) {
    int n = w.size();

    vector<pii> v(n);
    for (int i = 0; i < n; i++) v[i].first = w[i], v[i].second = i;

    sort(v.begin(), v.end());

    pref[0] = v[0].first;
    for (int i = 1; i < n; i++) pref[i] = pref[i - 1] + v[i].first;

    suff[0] = v.back().first;
    for (int i = 1; i < n; i++) suff[i] = suff[i - 1] + v[n - i - 1].first;



    int len = -1;

    for (int i = 0; i < n; i++)
    {
        if (pref[i] <= u && suff[i] >= l)
        {
            len = i + 1;
            break;
        }
    }


    if (len == -1)
    {
        // Impossible
        return vector <int>();
    }

    ll val = suff[len - 1];


    int i = 0;
    while (val > u)
    {
        val += v[i].first - v[n - i - 1].first;
        swap(v[i], v[n - i - 1]);
        i++;
    }

    vector <int> output(len);
    for (int &i : output)
    {
        i = v.back().second;
        v.pop_back();
    }

    return output;
}

• Subtask 1: 9 / 9
• Subtask 2: 10 / 10
• Subtask 3: 12 / 12
• Subtask 4: 15 / 15
• Subtask 5: 23 / 23
• Subtask 6: 31 / 31