Submission #577070

#	Time	Username	Problem	Language	Result	Execution time	Memory
577070		shezitt	Arranging Shoes (IOI19_shoes)	C++14	45 / 100	102 ms	139256 KiB

shoes

#include "shoes.h"
#include <iostream>
#include <queue>
 
using namespace std;
 
const int mxN = 2e5;
long long T[mxN+5];
int n;
 
void add(int i, int x){
	while(i <= mxN){
		T[i] += x;
		i += i & -i;
	}
}
 
long long query(int i){
	long long sum = 0;
	while(i > 0){
		sum += T[i];
		i -= i & -i;
	}
	return sum;
}
 
long long count_swaps(vector<int> s) {
	n = int(s.size())/2;
	vector<int> b(mxN+5);
	vector<queue<int>> pos(mxN+5);
	int c = 1;
	for(int i=0; i<2*n; ++i){
		if(s[i] < 0){
			b[i] = c++;
			pos[-s[i]].push(c++);
		}
	}
	for(int i=0; i<2*n; ++i){
		if(s[i] > 0){
			b[i] = pos[s[i]].front();
			pos[s[i]].pop();
		}
	}
	long long ans = 0;
	for(int i=2*n-1; i>=0; --i){
		ans += query(max(1, b[i]-1));
		add(b[i], 1);
	}
	return ans;
}

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