Submission #601556

#	Time	Username	Problem	Language	Result	Execution time	Memory
601556		Apiram	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	1 ms	212 KiB

shoes

#include "shoes.h"
#include<bits/stdc++.h>
using namespace std;
long long count_swaps(std::vector<int> s) {
	int n = s.size() / 2;
	vector<queue<int>>pos(n + 1),neg(n + 1);
	for (int i = 0;i<2*n;++i){
		if (s[i] > 0){
			pos[s[i]].push(i);
		}
		else{
			neg[-s[i]].push(i);
		}
	}
	int cnt = 0;
	vector<int>label(2 * n);
	for (int i = 0;i<2 * n;++i){
		if (s[i] > 0){
			if (!pos[s[i]].empty() && pos[s[i]].front() == i){
				label[pos[s[i]].front()] = cnt + 1;
				label[neg[s[i]].front()] = cnt;
				pos[s[i]].pop();
				neg[s[i]].pop();
				cnt+=2;
			}
		}
		else{
			if (!neg[-s[i]].empty() && neg[-s[i]].front() == i){
				label[pos[-s[i]].front()] = cnt + 1;
				label[neg[-s[i]].front()] = cnt;
				pos[-s[i]].pop();
				neg[-s[i]].pop();
				cnt+=2;
			}
		}
	}
	auto merge = [&](int left,int mid,int right){
		long long ans = 0;
		int i = left,j = mid + 1,k = 0;
		vector<int>temp(right - left + 1);
		while(i <=mid && j<=right){
			if (label[i] < label[j]){
				temp[k++] = label[i++];
			}
			else{
				ans+=mid - i + 1;
				temp[k++] = label[j++];
			}
		}
		while(i<=mid){
			temp[k++] = label[i++];
		}
		while(j<=right){
			temp[k++] = label[j++];
		}
		int p = left;
		while(left<=right){
			label[left] = temp[left - p];
			++left; 
		}
		return ans;
	};
	function<long long(int,int)>merge_sort = [&](int left,int right){
		if (left >= right)return 0LL;
		long long ans = 0;
		int mid = (left + right)>>1;
		ans+=merge_sort(left,mid);
		ans+=merge_sort(mid + 1,right);
		ans+=merge(left,mid,right);
		return ans;
	};
	return merge_sort(0,2 * n);
}

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