Submission #298251

#	Time	Username	Problem	Language	Result	Execution time	Memory
298251		Rayaabualjamal	Arranging Shoes (IOI19_shoes)	C++14	65 / 100	1081 ms	2048 KiB

shoes

#include "shoes.h"
#include <iostream> 
#include <vector> 
#include <cstdio>
#define rep(i,a,b) for(int i = a; i<b; i++)
#define per(i,a,b) for(int i = a; i>b; i--)
#define pb push_back
using namespace std;
long long count_swaps(vector<int> s) {
	int n = s.size()/2;
	bool f = 1;
	rep(i,0,n)if(s[i]>0)f = 0;
	rep(i,n,n+n)if(s[i]<0)f = 0;
	rep(i,0,n)if(s[i]!=(-s[i+n]))f = 0;
	if(f){
		long long ans = 0;
		rep(i,0,n){
			ans+= i;
		}
		return ans;
	}
	n*=2;
	long long ans = 0; 
	rep(i,0,n){
		if(s[i]<0){
			int pos;
			rep(j,i+1,n){
				if((-s[i]) == s[j]){
					pos = j;
					break;
				}
			}
			per(j,pos, i+1){
				swap(s[j], s[j-1]);
				ans++;
			}
		}else{
			int pos;
			rep(j,i+1,n){
				if((-s[i]) == s[j]){
					pos = j;
					break;
				}
			}
			per(j,pos, i){
				swap(s[j], s[j-1]);
				ans++;
			}
		}
		//cout << s[i] << endl;
		i++;
	}
	//cout << "ans: " << ans << endl;
	return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:38:8: warning: 'pos' may be used uninitialized in this function [-Wmaybe-uninitialized]
   38 |    int pos;
      |        ^~~
shoes.cpp:26:8: warning: 'pos' may be used uninitialized in this function [-Wmaybe-uninitialized]
   26 |    int pos;
      |        ^~~

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