Submission #776720

#	Time	Username	Problem	Language	Result	Execution time	Memory
776720		Warinchai	Arranging Shoes (IOI19_shoes)	C++14	50 / 100	209 ms	277892 KiB

shoes

#include "shoes.h"
#include<bits/stdc++.h>
using namespace std;
queue<int>q[100005];
queue<int>nq[100005];
int check[100005];
struct fenwick{
	int info[100005];
	void upd(int idx,int val){
		for(int i=idx;i<=100000;i+=i&-i){
			info[i]+=val;
		}
	}
	int fsum(int idx){
		int sum=0;
		for(int i=idx;i>0;i-=i&-i){
			sum+=info[i];
		}
		return sum;
	}
}fw;
long long count_swaps(vector<int>s) {
	//cout<<"work"<<endl;
	for(int i=0;i<s.size();i++){
		if(s[i]>=0){
			q[s[i]].push(i+1);
		}else{
			nq[s[i]*-1].push(i+1);
		}
	}
	long long ans=0;
	for(int i=0;i<s.size();i++){
		if(check[i]==0){
			int x=s[i];
			int nx=s[i]*-1;
			if(x>=0){
				int id=nq[nx*-1].front();
				nq[nx*-1].pop();
				q[x].pop();
				int sz=id-1-i;
				int st=i+1;
				//cout<<"id,i:"<<id<<" "<<i+1<<endl;
				//cout<<sz<<" ";
				sz-=fw.fsum(id)-fw.fsum(st);
				//cout<<sz<<endl;
				ans+=sz;
				check[i]=1;
				check[id-1]=1;
				fw.upd(id,1);
			}else{
				int id=q[nx].front();
				q[nx].pop();
				nq[nx].pop();
				//cout<<"id,i:"<<id<<" "<<i+1<<endl;
				int sz=id-2-i;
				int st=i+1;
				//cout<<sz<<" ";
				sz-=fw.fsum(id)-fw.fsum(st);
				ans+=sz;
				//cout<<sz<<endl;
				check[i]=1;
				check[id-1]=1;
				fw.upd(id,1);
			}
		}
	}
	//cout<<ans<<endl;
	return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:24:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |  for(int i=0;i<s.size();i++){
      |              ~^~~~~~~~~
shoes.cpp:32:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |  for(int i=0;i<s.size();i++){
      |              ~^~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 15
• Subtask 5: 20 / 20
• Subtask 6: 0 / 15