Submission #583681

#	Time	Username	Problem	Language	Result	Execution time	Memory
583681		joelau	Arranging Shoes (IOI19_shoes)	C++14	50 / 100	1087 ms	6220 KiB

shoes

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

long long N;
pair<long long,long long> A[100005], B[100005];

long long count_swaps(vector<int> s) {
	N = s.size()/2;
	long long ans = 0;
	for (long long i = 0; i < N; ++i) {
		for (long long j = 0; j < N; ++j) A[j] = B[j] = make_pair(4e18,4e18);
		long long cnt = 0;
		for (long long j = 0; j < N*2; ++j) {
			if (s[j] == 0) continue;
			if (s[j] > 0) A[s[j]-1] = min(A[s[j]-1],make_pair(cnt++,j));
			else B[-s[j]-1] = min(B[-s[j]-1],make_pair(cnt++,j));
		}
		pair<long long,long long> x = make_pair(4e18,4e18);
		for (long long j = 0; j < N; ++j) if (A[j].first != -1 && B[j].first != -1) {
			long long val = A[j].first + B[j].first;
			if (B[j].first < A[j].first) val--;
			x = min(x,make_pair(val,j));
		}
		ans += x.first;
		s[A[x.second].second] = s[B[x.second].second] = 0;
	}
	return ans;
}

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