Submission #592918

#	Time	Username	Problem	Language	Result	Execution time	Memory
592918		Mahtimursu	Detecting Molecules (IOI16_molecules)	C++17	100 / 100	51 ms	10288 KiB

molecules

#include "molecules.h"
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

vector<int> find_subset(int l, int u, vector<int> w) {
    int n = w.size();
    vector<pair<ll, int>> v(n);
    for (int i = 0; i < n; ++i) v[i] = {w[i], i};
    sort(v.begin(), v.end());

    vector<ll> pref(n), suf(n);

    for (int i = 0; i < n; ++i) {
        pref[i] = v[i].first;
        if (i != 0) pref[i] += pref[i - 1];
    }
    for (int i = n - 1; i >= 0; --i) {
        suf[i] = v[i].first;
        if (i != n - 1) suf[i] += suf[i + 1];
    }

    // Find max k for which pref[k] <= u
    int k = 0;
    for (; k < n; ++k) {
        if (pref[k] > u) {
            k--;
            break;
        }
    }
    if (k == n) k--;

    if (k == -1 || suf[n - k - 1] < l) return vector<int>(0);

    int left = 0;
    int right = k;
    ll cs = pref[k];

    vector<int> ans;

    while (true) {
        if (cs >= l && cs <= u) {
            for (int i = left; i <= right; ++i) {
                ans.push_back(v[i].second);
            }
            break;
        }
        if (right == n - 1) break;
        cs -= v[left++].first;
        cs += v[++right].first;
    }
 
    return ans;
}

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