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Micro-Drill #120 — Fast power (iterative)

Interval & Math Target: 15s

Iterative binary exponentiation handles negative exponents. Same as pow(x, n).

def power(x, n):
    res = 1
    if n < 0: x, n = 1/x, -n
    while n:
        if n & 1: res *= x
        x *= x
        n >>= 1
    return res

Type it from memory. Go.

Practice Problems

• 50. Pow(x, n)
• 372. Super Pow

Related Coding Drills

• Drill #49 — Power x^n (fast exponentiation) Medium
• Drill #84 — Power of two Easy