Submission #573070

#	Time	Username	Problem	Language	Result	Execution time	Memory
573070		sff_user	Arranging Shoes (IOI19_shoes)	C++17	0 / 100	1 ms	212 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
 
#define vi vector<int>
#define ll long long
 
using namespace std;
 
ll count_swaps(vector<int> s){
	int n = s.size() / 2;
	ll ans = 0;
	int pref[2*n];
	int encZ=0;
	int l,r;
	for(int i = 0 ; i < 2*n ; i++){
		if(s[i]<0){
			l=i;
			break;
		}
	}
	for(int i = 0 ;i < 2*n ; i++){
		if(s[i]>0){
			r=i;
			break;
		}
	}
	for(int i = 0 ; i < 2*n ; i++){
		if(s[i]==0){
			encZ++;
			pref[i]=encZ;
			continue;
		}
		if(s[i] < 0){
			ans += r-l-1-(pref[r]-pref[max(l-1,0)]);
			s[r]=0;
			for(int j = l+1 ; j < 2*n ; j++){
				if(s[j] <0){
					l=j;
					break;
				}
			}
			for(int j = r ; j < 2*n ; j++){
				if(s[j]>0){
					r=j;
					break;
				}
			}
		}
		else{
			ans += l-r-(pref[l]-pref[max(r-1,0)]);
			s[l] = 0;
			for(int j = r+1 ; j < 2*n ; j++){
				if(s[j] >0){
					r=j;
					break;
				}
			}
			for(int j = l+1 ; j < 2*n ; j++){
				if(s[j]<0){
					l=j;
					break;
				}
			}
		}
	}
	return ans;
}
 
// int main(){
// 	int p=1,n=-1;
// 	cout << count_swaps({p,n,n,n,n,p,p,n,p,p,p,n,n,p}) << endl;
// }
 

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:36:12: warning: 'l' may be used uninitialized in this function [-Wmaybe-uninitialized]
   36 |    for(int j = l+1 ; j < 2*n ; j++){
      |            ^

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