Submission #473978

#	Time	Username	Problem	Language	Result	Execution time	Memory
473978		cs71107	Detecting Molecules (IOI16_molecules)	C++14	100 / 100	76 ms	5188 KiB

molecules

#include "molecules.h"

#include <bits/stdc++.h>
#define f first
#define s second

using namespace std;

typedef long long ll;
typedef pair<int,int> pii;

const int MAXN = 2e5+10;

pii A[MAXN];
ll psum[MAXN];

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

    for(int i=1;i<=n;i++){
        A[i] = pii(w[i-1],i-1);
    }

    sort(A+1,A+n+1);

    for(int i=1;i<=n;i++){
        psum[i] = psum[i-1]+(ll)A[i].f;
    }

    ll lsum = 0;
    ll rsum = 0;

    ll curv = 0;
    ll lv = 0;
    ll rv = 0;

    vector<int> ans;

    int idx = 1;

    for(int i=1;i<=n;i++){

        lsum += (ll)A[i].f;
        rsum += (ll)A[n+1-i].f;

        if(lsum>u)break;
        if(rsum<l)continue;

        if(lsum>=l){
            for(int j=1;j<=i;j++){
                ans.push_back(A[j].s);
            }
        }
        else if(rsum<=u){
            for(int j=1;j<=i;j++){
                ans.push_back(A[n+1-j].s);
            }
        }
        else {
            
            idx = 1;
            curv = 0;

            for(int j=i-1;j>=0;j--){
                
                while(idx<=n){
                    
                    lv = curv + A[idx].f + (psum[idx+j]-psum[idx]);
                    rv = curv + A[idx].f + (psum[n]-psum[n-j]);

                    if(lv<=l&&u<=rv)break;

                    idx++;
                }

                assert(idx<=n);

                ans.push_back(A[idx].s);
                curv += (ll)A[idx].f;
                
                lv = curv + (psum[idx+j]-psum[idx]);
                rv = curv + (psum[n]-psum[n-j]);

                if(l<=lv&&lv<=u){
                    for(int t=idx+1;t<=idx+j;t++){
                        ans.push_back(A[t].s);
                    }
                    break;
                }
                else if(l<=rv&&rv<=u){
                    for(int t=n-j+1;t<=n;t++){
                        ans.push_back(A[t].s);
                    }
                    break;
                }

                idx++;
            }
        }

        break;
    }

    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