TripletSum.py

# Python3 program to find a triplet
 
# returns true if there is triplet
# with sum equal to 'sum' present
# in A[]. Also, prints the triplet
def find3Numbers(A, arr_size, sum):
 
    # Sort the elements
    A.sort()
 
    # Now fix the first element
    # one by one and find the
    # other two elements
    for i in range(0, arr_size-2):
     
 
        # To find the other two elements,
        # start two index variables from
        # two corners of the array and
        # move them toward each other
         
        # index of the first element
        # in the remaining elements
        l = i + 1
         
        # index of the last element
        r = arr_size-1
        while (l < r):
         
            if( A[i] + A[l] + A[r] == sum):
                print("Triplet is", A[i],
                     ', ', A[l], ', ', A[r]);
                return True
             
            elif (A[i] + A[l] + A[r] < sum):
                l += 1
            else: # A[i] + A[l] + A[r] > sum
                r -= 1
 
    # If we reach here, then
    # no triplet was found
    return False
 
# Driver program to test above function
A = [1, 4, 45, 6, 10, 8]
sum = 22
arr_size = len(A)
 
find3Numbers(A, arr_size, sum)