#include "shoes.h" #include <bits/stdc++.h> #define ll long long #define emb emplace_back #define em emplace #define all(a) a.begin(), a.end() #define rall(a) a.rbegin(), a.rend() #define pii pair <int, int> using namespace std; ll count_swaps(vector<int> a) { int n = a.size(); ll ans = 0; for (int i = 0; i < 2*n; i++) { if (i % 2 == 0) { if (a[i] < 0 && a[i + 1] == -1 * a[i]) { continue; } if (a[i] < 0) { int cur = 0; for (int j = i + 1; j < 2*n; j++) { if (a[j] == -1 * a[i]) { cur = j; break; } } int cnt = 0; while (cur > i + 1) { swap(a[cur], a[cur - 1]); cur--; cnt++; } ans += cnt; } else { int cur = 0; for (int j = i + 1; j < 2*n; j++) { if (a[j] == -1 * a[i]) { cur = j; break; } } int cnt = 0; while (cur > i) { swap(a[cur], a[cur - 1]); cur--; cnt++; } ans += cnt; } } else { if (a[i] > 0 && a[i - 1] == -1 * a[i]) { continue; } } } return ans; } /* sub3: find closest position sub4: -1 1 : 0 -1 -2 1 2 : 1 -1 -2 -3 1 2 3 : 3 ans = n(n-1)/2 sub5: n^2 for each idx i: find closest left/right shoe then just count number of swaps, then change index of other shoes accordingly..? _,_,_,X,_,_,Y,_,X,_,_,Y */