Submission #722842

#	Time	Username	Problem	Language	Result	Execution time	Memory
722842		victor_gao	Arranging Shoes (IOI19_shoes)	C++17	10 / 100	4 ms	5004 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
vector<int>all[100015][2];
int n;
struct BIT{
	int arr[100015];
	void modify(int p,int c){
		for (;p<=n;p+=(p&-p))
			arr[p]+=c;
	}
	int query(int p){
		int ans=0;
		for (;p>0;p-=(p&-p))
			ans+=arr[p];
		return ans;
	}
}bit;
long long count_swaps(std::vector<int> s) {
	n=s.size();
	for (int i=0;i<n;i++){
		if (s[i]<0) all[abs(s[i])][0].push_back(i+1);
		else all[s[i]][1].push_back(i+1);
		bit.modify(i+1,1);
	}
	long long ans=0;
	for (int i=1;i<=n;i++){
		for (int j=0;j<all[i][0].size();j++){
			int p1=bit.query(all[i][0][j]),p2=bit.query(all[i][1][j]);
			if (p1>p2){
				ans=(ans+p1-p2);
				bit.modify(p2,1);
				bit.modify(p1+1,-1);
			}
			else {
				ans=(ans+p2-p1-1);
				bit.modify(p1,1);
				bit.modify(p2+1,-1);
			}
			//cout<<ans<<' '<<p1<<" "<<p2<<'\n';
		}
	}
	return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:28:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |   for (int j=0;j<all[i][0].size();j++){
      |                ~^~~~~~~~~~~~~~~~~

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