递归的运行机制

野性酷女 2021-09-23 21:40 287阅读 0赞

## 以求数组元素的和为例讨论递归的运行机制 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjI5NTQz_size_16_color_FFFFFF_t_70]  
**模拟执行过程**

**第一步：**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjI5NTQz_size_16_color_FFFFFF_t_70 1]  
**第二步：**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjI5NTQz_size_16_color_FFFFFF_t_70 2]

package recursion;
    
    public class ArraySum { 
    
        public static int Sum(int[] arr) { 
            return Sum(arr, 0);
        }
    
        public static int Sum(int[] arr, int l) { 
            if (arr.length == l) { 
                return 0;
            } else { 
                return arr[l] + Sum(arr, l + 1);
            }
        }
    
        public static void main(String[] args) { 
            int[] arr = { 3, 10, 11, 22, 33, 44};
            int result = Sum(arr);
            System.out.println(result);
        }
    }

## 以删除链表中等于给定值 val 的所有节点为例讨论递归的运行机制 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjI5NTQz_size_16_color_FFFFFF_t_70 3]  
**将整个程序得执行分为如上图三步1、2、3**

**模拟执行过程**  
**第一步：**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjI5NTQz_size_16_color_FFFFFF_t_70 4]

**第二步：**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjI5NTQz_size_16_color_FFFFFF_t_70 5]

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