Arrays-Target Sum Triplets

#1

Please look into the code, it is not giving any output.

#2

Just dry run and check. Your 2-pointer approach is wrong. In the else case you are doing left++ and right-- which is not correct.
It is similar to array target sum pair problem.
Step 1: First Sort the array.
Step 2: Fix an element at i. Then find the rest two elements that sum to target in the similar way you have done the array target sum pair.

Consider the sorted array: [1 2 3 4 5 6 7]
Initially

  • i points to first element
  • l points to the left of the remaining array ie. to i+1
  • r points to the right of remaining array ie. to the last element.
    for every i:
    if(arr[l]+arr[r]+arr[i]==target)
    print the possibility, l++, r–

if(arr[l]+arr[r]+arr[i]>target)
r–

if(arr[l]+arr[r]+arr[i]<target)
l++

continue these steps till (l<r) -->after that increment i by one position and repeat the same steps.

For reference check this https://ide.codingblocks.com/s/261890

#3

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