Submission #831331

#	Time	Username	Problem	Language	Result	Execution time	Memory
831331		Supersonic	Detecting Molecules (IOI16_molecules)	C++14	100 / 100	42 ms	9476 KiB

molecules

#include "molecules.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
std::vector<int> find_subset(int l, int u, std::vector<int> w) {
    ll n=w.size();
    ll ls[n];ll rs[n];
    vector<pair<ll,ll>> s;
    for(ll i=0;i<n;i++)s.push_back({w[i],i});
    sort(s.begin(),s.end());
    ls[0]=s[0].first;rs[0]=s[n-1].first;
    ll b=-1;
    if(ls[0]<=l&&u<=rs[0])b=0;
    if(ls[0]>=l&&ls[0]<=u)b=0;
    if(rs[0]>=l&&rs[0]<=u)b=0;
    for(ll i=1;i<n;i++){
      ls[i]=ls[i-1]+s[i].first;rs[i]=rs[i-1]+s[n-1-i].first;
      if(ls[i]<=l&&u<=rs[i])b=i;
      if(ls[i]>=l&&ls[i]<=u)b=i;
      if(rs[i]>=l&&rs[i]<=u)b=i;
      //cerr<<ls[i]<<' '<<rs[i]<<endl;
    }
    //cerr<<b<<endl;
    if(b==-1)return {};
    vector<pair<ll,ll>> rr;
    ll lp=0;
    for(ll i=0;i<=b;i++){rr.push_back(s[i]);lp+=s[i].first;}
    ll ci=0;
    ll ib=b;
    while(lp<l){
      if(ci==rr.size())exit(1);
      if(s.size()==b)exit(1);
      auto y=s.back();s.pop_back();
      lp-=rr[ci].first;lp+=y.first;
      rr[ci]=y;
      if(lp>=l)break;
      ci++;
    }
    vector<int> r;
    for(auto i:rr)r.push_back(i.second);
    return r;
}
//6 7 8 8

Compilation message (stderr)

molecules.cpp: In function 'std::vector<int> find_subset(int, int, std::vector<int>)':
molecules.cpp:31:12: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |       if(ci==rr.size())exit(1);
      |          ~~^~~~~~~~~~~
molecules.cpp:32:18: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   32 |       if(s.size()==b)exit(1);
      |          ~~~~~~~~^~~
molecules.cpp:29:8: warning: unused variable 'ib' [-Wunused-variable]
   29 |     ll ib=b;
      |        ^~

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