Submission #966898

#	Time	Username	Problem	Language	Result	Execution time	Memory
966898		Hugo1729	Detecting Molecules (IOI16_molecules)	C++11	0 / 100	0 ms	348 KiB

molecules

#include <bits/stdc++.h>
#include "molecules.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<int,int>> sus;
    for(int i=0;i<n;i++)sus.push_back({w[i],i});

    sort(w.begin(),w.end());
    sort(sus.begin(),sus.end());
    ll pref[n+1];
    pref[0]=0;
    for(int i=0;i<n;i++)pref[i+1]=pref[i]+w[i];

    // for(int i=0;i<n+1;i++)cout << pref[i] << " ";
    // cout << '\n';

    int a=0,b=n;

    if(pref[n]<u)a=n;
    else if(pref[1]>u)return vector<int>(0);
    else{
        while(a<b-1){
            int mid = (a+b)/2;
            // cout << a << ' ' << b << ' ' << mid << '\n';
            if(pref[mid]<u)a=mid;
            else b=mid;
        }
    }
    
    if(a==0||pref[n]<l||pref[a]>u||pref[n]-pref[n-a]<l) return vector<int>(0);

    int c=0,d=a;

    while(c<d-1){
        int mid=(d+c)/2;
        // cout << c << ' ' << d << ' ' << mid << ' ' << pref[a-mid]+pref[n]-pref[n-mid] << '\n';
        if(pref[a-mid]+pref[n]-pref[n-mid]<u)c=mid;
        else d = mid;
    }

    if(pref[a-c]+pref[n]-pref[n-c]<u)c++;

    // cout << a << ' ' << c << '\n';

    vector<int> ans;
    for(int i=0;i<a-c;i++)ans.push_back(sus[i].second);
    for(int i=n-1;i>=n-c;i--)ans.push_back(sus[i].second);

    return ans;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 10
• Subtask 3: 0 / 12
• Subtask 4: 0 / 15
• Subtask 5: 0 / 23
• Subtask 6: 0 / 31