Divide and conquer — அடிப்படை

Split, recurse, merge.

Try this in Python

def sum_arr(a):
    if len(a) == 1:
        return a[0]
    m = len(a) // 2
    return sum_arr(a[:m]) + sum_arr(a[m:])

print(sum_arr([1, 2, 3, 4]))

Key takeaways

• Master theorem sketch.
• Combine cost.
• Skew depth.