Hamming Distance between two strings
You are given two strings of equal length, you have to find the Hamming Distance between these string.
Where the Hamming distance between two strings of equal length is the number of positions at which the corresponding character is different.
Examples:
Input : str1[] = "w3wiki", str2[] = "BeginnerandBeginner" Output : 3 Explanation : The corresponding character mismatch are highlighted. "BeginnerforBeginner" and "BeginnerandBeginner" Input : str1[] = "1011101", str2[] = "1001001" Output : 2 Explanation : The corresponding character mismatch are highlighted. "1011101" and "1001001"
This problem can be solved with a simple approach in which we traverse the strings and count the mismatch at the corresponding position. The extended form of this problem is edit distance.
Algorithm :
int hammingDist(char str1[], char str2[]) { int i = 0, count = 0; while(str1[i]!='\0') { if (str1[i] != str2[i]) count++; i++; } return count; }
Below is the implementation of two strings.
C++
// C++ program to find hamming distance b/w two string #include <bits/stdc++.h> using namespace std; // function to calculate Hamming distance int hammingDist(string str1, string str2) { int i = 0, count = 0; while (str1[i] != '\0' ) { if (str1[i] != str2[i]) count++; i++; } return count; } // driver code int main() { string str1 = "Beginnerpractice" ; string str2 = "nerdspractise" ; // function call cout << hammingDist(str1, str2); return 0; } // This code is contributed by Sania Kumari Gupta (kriSania804) |
C
// C program to find hamming distance b/w two string #include <stdio.h> // function to calculate Hamming distance int hammingDist( char * str1, char * str2) { int i = 0, count = 0; while (str1[i] != '\0' ) { if (str1[i] != str2[i]) count++; i++; } return count; } // driver code int main() { char str1[] = "Beginnerpractice" ; char str2[] = "nerdspractise" ; // function call printf ( "%d" , hammingDist(str1, str2)); return 0; } // This code is contributed by Sania Kumari Gupta // (kriSania804) |
Java
// Java program to find hamming distance b/w two string class GFG { // function to calculate Hamming distance static int hammingDist(String str1, String str2) { int i = 0 , count = 0 ; while (i < str1.length()) { if (str1.charAt(i) != str2.charAt(i)) count++; i++; } return count; } // Driver code public static void main(String[] args) { String str1 = "Beginnerpractice" ; String str2 = "nerdspractise" ; // function call System.out.println(hammingDist(str1, str2)); } } // This code is contributed by Sania Kumari Gupta // (kriSania804) |
Python3
# Python3 program to find # hamming distance b/w two # string # Function to calculate # Hamming distance def hammingDist(str1, str2): i = 0 count = 0 while (i < len (str1)): if (str1[i] ! = str2[i]): count + = 1 i + = 1 return count # Driver code str1 = "Beginnerpractice" str2 = "nerdspractise" # function call print (hammingDist(str1, str2)) # This code is contributed by avanitrachhadiya2155 |
C#
// C# program to find hamming // distance b/w two string using System; class GFG { // function to calculate // Hamming distance static int hammingDist(String str1, String str2) { int i = 0, count = 0; while (i < str1.Length) { if (str1[i] != str2[i]) count++; i++; } return count; } // Driver code public static void Main () { String str1 = "Beginnerpractice" ; String str2 = "nerdspractise" ; // function call Console.Write(hammingDist(str1, str2)); } } // This code is contributed by nitin mittal |
PHP
<?php // PHP program to find hamming distance b/w // two string // function to calculate // Hamming distance function hammingDist( $str1 , $str2 ) { $i = 0; $count = 0; while (isset( $str1 [ $i ]) != '' ) { if ( $str1 [ $i ] != $str2 [ $i ]) $count ++; $i ++; } return $count ; } // Driver Code $str1 = "Beginnerpractice" ; $str2 = "nerdspractise" ; // function call echo hammingDist ( $str1 , $str2 ); // This code is contributed by nitin mittal. ?> |
Javascript
<script> // JavaScript program to find hamming distance b/w // two string // function to calculate Hamming distance function hammingDist(str1, str2) { let i = 0, count = 0; while (i < str1.length) { if (str1[i] != str2[i]) count++; i++; } return count; } // driver code let str1 = "Beginnerpractice" ; let str2 = "nerdspractise" ; // function call document.write(hammingDist (str1, str2)); // This code is contributed by Manoj. </script> |
Output
4
Time complexity: O(n)
Note: For Hamming distance of two binary numbers, we can simply return a count of set bits in XOR of two numbers.