Submission #808665

#	Time	Username	Problem	Language	Result	Execution time	Memory
808665		KemalK	Arranging Shoes (IOI19_shoes)	C++17	10 / 100	1095 ms	145800 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
int n;
long long count_swaps(std::vector<int> s) {
	n = s.size();
	if (n == 2){
		if (s[0] < 0){
			return 0;
		}
		return 1;
	}
	map <int, deque<int>> pos_right;
	map <int, deque<int>> pos_left;
	for (int i = 0; i < n; i++){
		if (s[i] > 0){
			pos_right[s[i]].push_back(i);
		}
		else{
			pos_left[s[i]].push_back(i);
		}
	}
	ll ans = 0;
	vector <bool> used (n + 1, false);
	for (int i = 0; i < n; i++){
		if (!used[i]){
			// cout << i << "\n";
			// left;
			if (s[i] < 0){
				// cout << "left" << "\n";
				int nxt;
				for (int j = i + 1; j < n; j++){
					if (!used[j] and abs(s[i]) == s[j]){
						ans += (j - i - 1ll);
						nxt = j;
						break;
					}
				}
				for (int j = nxt; j > i + 1; j--){
					swap(s[j], s[j - 1]);
				}
				used[i] = true;
				used[i + 1] = true;
			}
			else{ // right
				// cout << "right" << "\n";
				int nxt;
				for (int j = i + 1; j < n; j++){
					if (!used[j] and s[i] == abs(s[j])){
						nxt = j;
						ans += (j - i);
						break;
					}
				}
				for (int j = nxt; j > i; j--){
					swap(s[j], s[j - 1]);
				}
				used[i] = true;
				used[i + 1] = true;
			}
		}
	}
	return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:57:14: warning: 'nxt' may be used uninitialized in this function [-Wmaybe-uninitialized]
   57 |      swap(s[j], s[j - 1]);
      |              ^
shoes.cpp:32:9: warning: 'nxt' may be used uninitialized in this function [-Wmaybe-uninitialized]
   32 |     int nxt;
      |         ^~~

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