Submission #966241

#	Time	Username	Problem	Language	Result	Execution time	Memory
966241		anango	Detecting Molecules (IOI16_molecules)	C++17	100 / 100	67 ms	12736 KiB

molecules

#include "molecules.h"
#include <bits/stdc++.h>
using namespace std;
#define int long long

bool overlap(int l1, int r1, int l2, int r2) {
    return !(max(l1,l2)>min(r1,r2));
}

vector<int32_t> find_subset(int32_t l, int32_t u, vector<int32_t> w) {
    //let a_i be min weight for a i-subset
    //b_i = max weight for a i-subset
    //if for some i, [a_i,b_i] overlaps [l,u], exists a solution
    //use a sliding window of length i
    int n=w.size();
    vector<pair<int,int>> elemind;
    for (int i=0; i<n; i++) {
        elemind.push_back({w[i],i});
    }
    sort(elemind.begin(), elemind.end());
    sort(w.begin(), w.end());
    vector<int> pref(n+1,0);
    for (int i=0; i<n; i++) {
        pref[i+1] = pref[i]+w[i];
    }
    vector<int> aval(n+1,0);
    vector<int> bval(n+1,0);
    for (int le=0; le<=n; le++) {
        aval[le] = pref[le] - pref[0];
        bval[le] = pref[n]-pref[n-le];
    }
    for (int le=0; le<=n; le++) {
        if (overlap(aval[le],bval[le],l,u)) {
            for (int st=0; st<=n-le; st++) {
                int tot = pref[st+le] - pref[st];
                //cout << le << " " << st << " " << tot << endl;
                if (l<=tot && tot<=u) {
                    vector<int32_t> ans;
                    for (int i=st; i<st+le; i++) {
                        ans.push_back(elemind[i].second);
                    }
                    sort(ans.begin(), ans.end());
                    return ans;
                }
            }
        }
    }
    return vector<int32_t>(0);
    
    
}

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