Submission #681150

#	Time	Username	Problem	Language	Result	Execution time	Memory
681150		Ronin13	Arranging Shoes (IOI19_shoes)	C++14	0 / 100	1 ms	212 KiB

shoes

#include <iostream>
#include <unordered_map>
#include "shoes.h"

using namespace std;

long long count_swaps(vector <int> shoes) {
  	long long n = shoes.size();
    unordered_map<long long, long long> size_count;
    for (long long i = 0; i < n; i++) {
        size_count[shoes[i]] = size_count[shoes[i]] + 1;
    }
    long long swaps = 0;
    for (long long i = 0; i < n; i++) {
        if (shoes[i] < 0) {
            continue;
        }
        long long matching_shoe = -shoes[i];
        if (size_count[matching_shoe] <= 0) {
            continue;
        }
        size_count[matching_shoe]--;
        long long j = i + 1;
        while (shoes[j] != matching_shoe) {
            j++;
        }
        swap(shoes[i], shoes[j]);
        swaps += j - i;
    }
    return swaps;
}

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