Submission #134605

#	Time	Username	Problem	Language	Result	Execution time	Memory
134605		ckodser	Detecting Molecules (IOI16_molecules)	C++14	100 / 100	142 ms	17888 KiB

molecules

#include "molecules.h"

#include<bits/stdc++.h>


#define ll long long
#define pb push_back
#define mp make_pair
#define pii pair<ll,ll>
#define F first
#define S second
#define ld long double

using namespace :: std;

const ll maxn=2e5+500;
const ll inf=1e9+900;

ll pr[maxn];
ll sa[maxn];

vector<int> find_subset(int l, int r,vector<int> W) {
    vector<pii> w;
    for(ll i=0;i<W.size();i++){
	w.pb(mp(W[i],i));
    }		
    sort(w.begin(),w.end());
    ll n=w.size();
    pr[0]=w[0].F;
    for(ll i=1;i<n;i++){
	pr[i]=pr[i-1]+w[i].F;
    }
    sa[n-1]=w[n-1].F;
    for(ll i=n-2;i>=0;i--){
	sa[i]=sa[i+1]+w[i].F;
    }
    vector<int> ans;
    for(ll t=1;t<=n;t++){
	if(l<=pr[t-1] && pr[t-1]<=r){
	    for(ll i=0;i<t;i++){
		ans.pb(w[i].S);
	    }
	    sort(ans.begin(),ans.end());
	    return ans;
	}
	if(l<=sa[n-t] && sa[n-t]<=r){
	    for(ll i=n-t;i<n;i++){
		ans.pb(w[i].S);
	    }
	    sort(ans.begin(),ans.end());

	    return ans;
	}
	if(pr[t-1]<l && r<sa[n-t]){
	    ll sum=pr[t-1];
	    set<ll> hast;
	    set<ll> nist;
	    for(ll i=0;i<t;i++)hast.insert(i);
	    for(ll i=t;i<n;i++)nist.insert(i);
	    while(sum<l){
		auto it=(hast.begin());
		sum-=(w[*it].F);
		hast.erase(it);
		
		auto ip=(nist.end());
		ip--;
		sum+=(w[*ip].F);
		nist.erase(ip);
		hast.insert(*ip);
	    }
	    for(auto e:hast){
		ans.pb(w[e].S);
	    }
	    sort(ans.begin(),ans.end());
	    return ans;
	}
    }
}

Compilation message (stderr)

molecules.cpp: In function 'std::vector<int> find_subset(int, int, std::vector<int>)':
molecules.cpp:24:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(ll i=0;i<W.size();i++){
                ~^~~~~~~~~
molecules.cpp:78:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

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