Submission #1144652

#	Time	Username	Problem	Language	Result	Execution time	Memory
1144652		crispxx	Arranging Shoes (IOI19_shoes)	C++20	30 / 100	88 ms	12156 KiB

shoes

#include <bits/stdc++.h>
#include "shoes.h"

// #include "grader.cpp"

using namespace std;

#define all(x) x.begin(), x.end()
#define pb push_back
#define nl '\n'

struct Fenw {
	int n;
	vector<int> t;
	
	Fenw(int n) : n(n), t(n + 1) {}
	
	void update(int i, int x) {
		i++;
		for(; i <= n; i += i & -i) t[i] += x;
	}
	int get(int i) {
		int res = 0;
		
		for(; i >= 1; i -= i & -i) res += t[i];
		
		return res;
	}
	
	int get(int l, int r) {
		return get(r + 1) - get(l);
	}
};

long long count_swaps(vector<int> s) {
	int n = s.size();
	
	long long ans = 0;
	
	Fenw fn(n);
	
	bool flag = 0;
	
	map<int, set<int>> st;
	
	for(int i = 0; i < n; i++) {
		st[s[i]].emplace(i);
	}
	
	for(int i = 0; i < n; i++) {
		if(fn.get(i, i)) continue;
		
		int x = s[i];
		
		if(flag != (x > 0)) {
			int y = -x;
			
			int j = *st[y].begin();
			st[y].erase(st[y].begin());
			
			ans += j - i - fn.get(i, j);
			fn.update(j, 1);
			
		} else flag = !flag;
		
		st[x].erase(i);
	}
	
	return ans;
}

/**
4
2 -2 2 2 -2 -2 -2 2

4
2 -2 2 -2 2 -2 2 -2

**/

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