CheckPerMutation.md

Contents

• Question
• Solution and Explanation in JavaScript
• Solution and Explanation in CPP
• Complexity

Question

Given two strings, write a method to decide if one is a permutation of the others

Solution and Explanation in JavaScript

View code

In the above solution we use JavaScript default function to get our expected output and another solution we use c++ sort function. In the solution we make a function named checkPermutation which takes two parameters firstString and secondString. First of all we check if the both string have same length of characters or not. If both string have same string length then we will proceed to our next step, if not then we will return false.
If both string have same length then we will split the string using split function with empty string split(''). Lets say, our first string is javascript. After splitting the string we get our string like this -

[
  'j', 'a', 'v', 'a',
  's', 'c', 'r', 'i',
  'p', 't'
]

Then we will sort the string using sort() function. After sorting our string will look like this -

[
  'a', 'a', 'c', 'i',
  'j', 'p', 'r', 's',
  't', 'v'
]

Then we will join our sorted string using join('') function and outcome will look like this aacijprstv.

We will do this for both of the string and check if the both string is equal or not. If equal then return true, if not then return false.

Solution and Explanation in CPP

View code

bool checkPermutation(string str1, string str2)
{
    sort(str1.begin(), str1.end());
    sort(str2.begin(), str2.end());

    if(str1 == str2) return true;

    return false;
}

View code

Complexity

Runtime Complexity: O(n log n)