Lcs of 3 strings

#1

cant find where my code is wrong
link:-

#2

Try using the bottom up approach. Its easier and simpler to understand.

#3

Your corrected code using top down approach

#4

why the condition is seperately used???

#5

and one more thing that is this syntax wrong return dp[i][j]=max(a,b); or its necessary to first assign and then return

#6

Hello @riprogerdep,

  1. He has only added a conditional check:
    if(n==0||m==0||k==0)
    {
    dp[n][m][k] = 0;
    return dp[n][m][k];

    }
    This implies that if the length of any of the three is 0 then the common length would also be zero.
    Because you are not considering any character from one of the string.
    Reason of writing this separately:
    As in the next if statement he comparing elements at n-1, k-1,m-1.
    So, if any of the n,m and k is 0, the index will become -1 which is not valid.
    Hence, you can remove the following statements as m, n, and k will never become negative:
    if(n<0||m<0||k<0)
    return 0;
    https://ide.codingblocks.com/s/186425

  2. No, the syntax is not wrong.
    As we know that the associativity of “=” i.e. assignment operator if from right to left.
    So, on executing return dp[i][j]=max(a,b);
    first, the max of a and b will be assigned to dp[i][j] then the value stored at dp[i][j] will be returned.

Hope, this would help.
Give a like if you are satisfied.

#7

thank you bhai for your very good explanation:)