Submission #730243

#	Time	Username	Problem	Language	Result	Execution time	Memory
730243		ETheBest3	Detecting Molecules (IOI16_molecules)	C++14	0 / 100	1 ms	340 KiB

molecules

#include<bits/stdc++.h>
//#include "molecules.h"
#define lli int
using namespace std;
vector<lli> ans;
vector<pair<lli, lli>> W;
lli N;
bool used[200005];
lli bin_search(lli l, lli r, lli x){
    if(l==r)return -1;
    while(l<r-1){
        lli mid=(l+r)/2;
        if(W[mid].first>x)l=mid;
        else r=mid;
    }
    if(W[l].first<=x)return l;
    if(W[r].first>x or r>=N)return -1;
    return r;
}
std::vector<int> find_subset(int l, int u, std::vector<int> w) {
    for(lli i=0; i<w.size(); i++)W.push_back({w[i], i});
    sort(W.begin(), W.end(), greater<pair<lli, lli>>());
    N=W.size();
    lli ost=l, ind=0, last=-1;
    bool fl=0;
    while(ost>0){
        ind=bin_search(last+1, N, ost);
        if(ind==-1){
            break;
        }
        used[ind]=1;
        ans.push_back(W[ind].second);
        ost-=W[ind].first;
        last=ind;
    }
    if(ost==0)return ans;
    if(ans.size()==0){
        if(W[N-1].first<=u){
            ans.push_back(W[N-1].second);
            return ans;
        }
        return vector<int>(0);
    }
    lli sum=l-ost, now=0;
    for(lli i=N-1; i>=0; i--){
        if(used[i])continue;
        if(sum+W[i].first<=u and sum+W[i].first>=l){
            ans.push_back(W[i].second);
            return ans;
        }
    }
    for(lli i=0; i<N; i++){
        if(used[i])continue;
        sum+=W[i].first-w[ans[ans.size()-1-now]];
        ans[ans.size()-1-now]=W[i].second;
        now++;
        if(sum>=l)break;
    }
    if(sum<l or sum>u)return vector<int>(0);
    return ans;
}

Compilation message (stderr)

molecules.cpp: In function 'std::vector<int> find_subset(int, int, std::vector<int>)':
molecules.cpp:21:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |     for(lli i=0; i<w.size(); i++)W.push_back({w[i], i});
      |                  ~^~~~~~~~~
molecules.cpp:25:10: warning: unused variable 'fl' [-Wunused-variable]
   25 |     bool fl=0;
      |          ^~

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