Submission #164446

#	Time	Username	Problem	Language	Result	Execution time	Memory
164446		cfalas	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	2 ms	376 KiB

shoes

#include<bits/stdc++.h>
using namespace std;
#include "shoes.h"
#define F first
#define S second
 
long long count_swaps(std::vector<int> s) {
	int n = s.size()/2;
	int swaps=0;
	int ind = 0;
	map<int, vector<int> > m;
	for(int i=0;i<s.size();i++){
		m[s[i]].push_back(i);
	}
	while(ind<s.size()){
		if(m[s[ind]].size()==0 || m[s[ind]][0]!=ind){
			ind++;
			continue;
		}
		if(s[ind]>0) swaps++;

		if(m[-s[ind]].size()==0) while(1) {}
		int i = m[-s[ind]][0];
		swaps += (i-ind-1);
		m[-s[ind]].erase(m[s[i]].begin());
		m[s[ind]].erase(m[s[ind]].begin());
		ind++;
	}
	return swaps;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:12:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<s.size();i++){
              ~^~~~~~~~~
shoes.cpp:15:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while(ind<s.size()){
        ~~~^~~~~~~~~
shoes.cpp:8:6: warning: unused variable 'n' [-Wunused-variable]
  int n = s.size()/2;
      ^

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