language-agnostic - 递归如何使运行时内存的使用变得不可预测？

Question

引自 Code Complete 2 ,

int Factorial( int number ) {
   if ( number == 1 ) {
      return 1;
   }
   else {
      return number * Factorial( number - 1 );
   }
}

In addition to being slow ^[1] and making the use of run-time memory unpredictable ^[2], the recursive version of this routine is harder to understand than the iterative version, which follows:

int Factorial( int number ) {
   int intermediateResult = 1;
   for ( int factor = 2; factor <= number; factor++ ) {
      intermediateResult = intermediateResult * factor;
   }
   return intermediateResult;
}

我认为缓慢的部分是因为不必要的函数调用开销。

但是递归如何使运行时内存的使用变得不可预测？

我们不能总是预测需要多少内存(因为我们知道递归应该何时结束)？我认为它会像迭代案例一样不可预测，但不再是了。

Answer 1

由于递归方法反复调用自己，需要大量的堆栈内存。由于栈是有限的，超出栈内存就会出错。