1. // User function Template for Java
  2.  
  3. class Solution {
  4.     /**
  5.      * Find the LCS of both strings
  6.      * Once LCS length is found, we can remove the length of LCS from both the strings
  7.      * and then we can sum up the remaining length of both strings
  8.      */
  9.     public int minOperations(String s1, String s2) {
  10.         int n = s1.length();
  11.         int m = s2.length();
  12.  
  13.         // step-1 create a matrix of LCS
  14.         int[][] t = new int[n+1][m+1];
  15.  
  16.         // step-2 initialise the matrix
  17.         for(int i=0; i<n+1; i++)
  18.         {
  19.             for(int j=0; j<m+1; j++)
  20.             {
  21.                 // when string is empty, no LCS found
  22.                 if(i == 0 || j == 0)
  23.                     t[i][j] = 0;
  24.             }
  25.         }
  26.  
  27.         // step-3 LCS iterative code
  28.         for(int i=1; i<n+1; i++)
  29.         {
  30.             for(int j=1; j<m+1; j++)
  31.             {
  32.                 if(s1.charAt(i-1) == s2.charAt(j-1))
  33.                     t[i][j] = 1 + t[i-1][j-1];
  34.  
  35.                 else
  36.                     t[i][j] = Math.max(t[i-1][j], t[i][j-1]);
  37.             }
  38.         }
  39.  
  40.         int lcsLength = t[n][m];
  41.  
  42.         int deletion = n-lcsLength;
  43.         int insertion = m-lcsLength;
  44.  
  45.         return deletion+insertion;
  46.     }
  47. }