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知识点：数据结构 2/10（单选/必答） What is the time...

Question

知识点：数据结构 2/10（单选/必答）
What is the time complexity of the following function regarding N?
int fib(int N) {
  if (N < 2) {
    return 1
  }
  return fib(N-1) + fib(N-2)
}

A. Constant time.

B. Logarithmic time.

C. Linear time.

D. Polynomial time.

E. Exponential time.