[HackerRank] Sorting: Bubble Sort (Sorting)

C++

#include <bits/stdc++.h>

using namespace std;

vector<string> split_string(string);

// Complete the countSwaps function below.
void countSwaps(vector<int> a) {
    int count=0;
    for(int i=0; i<a.size(); i++){
        for(int j=0; j<a.size()-1; j++){
            if(a[j]>a[j+1]) { 
                swap(a[j], a[j+1]); 
                count += 1;
            }
            
        }
    }
    cout << "Array is sorted in " << count << " swaps." << endl;
    cout << "First Element: " << a.front() << endl;
    cout << "Last Element: " << a.back() << endl;
}

int main()
{
    int n;
    cin >> n;
    cin.ignore(numeric_limits<streamsize>::max(), '\n');

    string a_temp_temp;
    getline(cin, a_temp_temp);

    vector<string> a_temp = split_string(a_temp_temp);

    vector<int> a(n);

    for (int i = 0; i < n; i++) {
        int a_item = stoi(a_temp[i]);

        a[i] = a_item;
    }

    countSwaps(a);

    return 0;
}

vector<string> split_string(string input_string) {
    string::iterator new_end = unique(input_string.begin(), input_string.end(), [] (const char &x, const char &y) {
        return x == y and x == ' ';
    });

    input_string.erase(new_end, input_string.end());

    while (input_string[input_string.length() - 1] == ' ') {
        input_string.pop_back();
    }

    vector<string> splits;
    char delimiter = ' ';

    size_t i = 0;
    size_t pos = input_string.find(delimiter);

    while (pos != string::npos) {
        splits.push_back(input_string.substr(i, pos - i));

        i = pos + 1;
        pos = input_string.find(delimiter, i);
    }

    splits.push_back(input_string.substr(i, min(pos, input_string.length()) - i + 1));

    return splits;
}

• swap이 발생하는 반복문 내 if문에서 swap 후 count를 증가시킨다.
• 이후 문제에서 출력하라는 swap 개수(count), 첫 번째 원소(a.front()), 마지막 원소(a.back())을 출력한다.

Python

#!/bin/python3

import math
import os
import random
import re
import sys

# Complete the countSwaps function below.
def countSwaps(a):
    count=0
    for i in range(0,len(a)):        
        for j in range(0, len(a)-1):
            if a[j] > a[j+1]:
                temp=a[j]
                a[j]=a[j+1]
                a[j+1]=temp
                count += 1
    print("Array is sorted in "+str(count)+" swaps.")   
    print("First Element: "+str(a[0])) 
    print("Last Element: "+str(a[len(a)-1]))       

if __name__ == '__main__':
    n = int(input())

    a = list(map(int, input().rstrip().split()))

    countSwaps(a)

• python의 경우 별도의 swap 함수가 없어서 직접 바꿔준다. 다른 부분은 C++과 동일