Submission #143481

#	Time	Username	Problem	Language	Result	Execution time	Memory
143481		dolphingarlic	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	249 ms	139032 KiB

shoes

#include "shoes.h"
#include <queue>

int n;
long long bit[200001];
std::queue<int> left[100001], right[100001];

void update(int pos) { for (int i = pos; i <= n; i += (i & (-i))) bit[i]++; }
long long query(int l, int r) {
	long long ans = 0;
	for (int i = r; i > 0; i -= (i & (-i))) ans += bit[i];
	for (int i = l; i > 0; i -= (i & (-i))) ans -= bit[i];
	return ans;
}

long long count_swaps(std::vector<int> s) {
	n = s.size();
	for (int i = 0; i < n; i++) {
		if (s[i] < 0) left[-s[i]].push(i + 1);
		else right[s[i]].push(i + 1);
	}

	long long ans = 0;
	for (int i = 0; i < n; i++) {
		if (s[i] < 0) {
			if (left[-s[i]].front() == i + 1) {
				int r_indx = right[-s[i]].front();
				right[-s[i]].pop();
				left[-s[i]].pop();

				ans += r_indx - i - 2 - query(i + 1, r_indx);
				update(r_indx);
			}
		} else {
			if (right[s[i]].front() == i + 1) {
				int l_indx = left[s[i]].front();
				right[s[i]].pop();
				left[s[i]].pop();

				ans += l_indx - i - 1 - query(i + 1, l_indx);
				update(l_indx);
			}
		}
	}
	return ans;
}

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