遞歸最終數目

Question

如果我輸入的號碼是2 ......據我所知，該函數將以前的答案乘以2，直到數將大於25

2 * 2 = 4

4 * 2 = 8

8 * 2 = 16

16 * 2 = 32 ...程序停止，因爲num是32

但然後我的最終數62如何會收到該號碼>

#include <iostream> 
using namespace std; 

int myRecursiveFunction (int num) 
{ 
    if (num >= 25)   // stopping condition 
     return num; 
    else 
     cout << "number is at " << num << endl; 
     return num = num + myRecursiveFunction (num * 2); 
} 
int main() 
{ 
    int num, num1; 
    cout << "Enter a number: "; 
    cin >> num; 
    num1 = myRecursiveFunction(num); 
    cout << "Final number is: " << num1; 
    return 0; 
} 

Answer 1

2 + 4 + 8 + 16 + 32 = 62。
返回值每次都獲取添加。

Answer 2

你想這樣做：

2 * 2 = 4

4 * 2 = 8

8 * 2 = 16

16 * 2 = 32 ...程序因爲num是32而停止

你正在做 return num = num + myRecursiveFunction（num * 2）; 返回32 + 16 + 8 + 4 + 2 = 62