Submission #1047288

#	Time	Username	Problem	Language	Result	Execution time	Memory
1047288		Onur_Ilgaz	Arranging Shoes (IOI19_shoes)	C++17	50 / 100	273 ms	146620 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;

struct fw {
	int n;
	vector <int> t;
	fw(int size): n(size), t(n + 1) {}
	void update(int ind, int x) {
		while(ind <= n) {
			t[ind] += x;
			ind += ind & (-ind);
		}
	}
	int query(int ind) {
		int ans = 0;
		while(ind) {
			ans += t[ind];
			ind -= ind & (-ind);
		}
		return ans;
	}
};

long long count_swaps(std::vector<int> s) {
	fw t(s.size());
	map <int, queue<int> > mp;
	int ans = 0;
	for(int i = 0; i < s.size(); i++) {
		if(!mp[-s[i]].empty()) {
			int ind = mp[-s[i]].front();
			t.update(ind + 2, 1);
			t.update(i + 1, -1);
			ind += t.query(ind + 1);
			// cout << i << " " << ind << "\n";
			mp[-s[i]].pop();
			ans += (i - ind) - (s[i] > 0);
		}
		else {
			mp[s[i]].push(i);
		}
	}
	return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:29:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |  for(int i = 0; i < s.size(); i++) {
      |                 ~~^~~~~~~~~~

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