java - 递归深度 - Java 中的制表符和凹痕

Question

我想格式化我的 Java 程序输出，以便我可以看到递归的“深度”。怎么做？ 不要迷失在我的递归树中是非常重要的。

示例输出(用于从 0 开始计算第 n 个数字的简单递归函数):

This is the first recursive call. Input value: 3.
    This is the second recursive call. Input value: 2.
        This is the 3rd recursive call. Input value: 1.
        Output value : 1.
    This is again the second recursive call. Input value: 2.
    Output value : 1 + 1.
This is again the first recursive call. Input value: 3.
Output value : 1 + 1 + 1.

Answer 1

您可以使用代表您有多深的变量(如 level)。它从 1 开始，并在每次递归调用时递增。

public static void main(String[] args) {
    function(3, 1);
}

public static String function(int input, int level) {
    String tab = "";
    for (int i = 0; i < level - 1; i++) {
        tab += "\t";
    }
    System.out.println(tab + "This is the " + level + " recursive call. Input value: " + input);
    if (input == 1) {
        System.out.println(tab + "Output value: 1");
        return "1";
    }
    String output = function(input - 1, level + 1);
    System.out.println(tab + "This is again the " + level + " recursive call. Input value: " + input);
    System.out.println(tab + "Output value: " + output + " + 1");
    return output + " + 1";
}