尝试编写一个简单的程序来测试Collatz猜想中的数字

Question

我只是想通过说我是一个编程新手来开始这件事。这可能是我写过的最高级的代码。

我正在尝试测试Collatz猜想中的数字。我的输入变量应该在循环到1之后加1。如果不是1，那么它就会转到其他2个函数。如果数是偶数，则除以2；如果是奇数，则乘以3，再加上1。

这个数学方程之所以如此有趣，是因为我们不知道是否所有的数字都有足够的次数通过这个方程。

我也知道在循环中没有中断，但这不是问题所在。我的问题是输出。下面是我的代码：

public class class1 {

static int output = 0;
static int input = 1;
static int turn = 0;

public static void main(String[] args) {
    output = input;
    for (;;) {
        if(input != 1){
            if (input % 2 == 0) {
                even(input);
                System.out.println("output = " + input + " turn = " + turn);
            } else if (input % 2 == 1) {
                odd(input);
                System.out.println("output = " + input + " turn = " + turn);
            }
        }else{
            System.out.println("done in " + turn + " turns");
            turnsTested++;
            turn = 0;
            output = input;
        }
        turn++;
    }
}//end main


public static int even(int input2) {
    input = input / 2;
    return input;

}

public static int odd(int input2) {
    input = (input * 3);
    input++;
    return input;
     }
}//end class

运行以下代码的输出：

output = 2734 turn = 105

output = 1367 turn = 106

output = 4102 turn = 107

output = 2051 turn = 108

output = 6154 turn = 109

output = 3077 turn = 110

output = 9232 turn = 111

output = 4616 turn = 112

output = 2308 turn = 113

output = 1154 turn = 114

output = 577 turn = 115

output = 1732 turn = 116

output = 866 turn = 117

output = 433 turn = 118

output = 1300 turn = 119

output = 650 turn = 120

output = 325 turn = 121

output = 976 turn = 122

output = 488 turn = 123

output = 244 turn = 124

output = 122 turn = 125

output = 61 turn = 126

output = 184 turn = 127

output = 92 turn = 128

output = 46 turn = 129

output = 23 turn = 130

output = 70 turn = 131

output = 35 turn = 132

output = 106 turn = 133

output = 53 turn = 134

output = 160 turn = 135

output = 80 turn = 136

output = 40 turn = 137

output = 20 turn = 138

output = 10 turn = 139

output = 5 turn = 140

output = 16 turn = 141

output = 8 turn = 142

output = 4 turn = 143

output = 2 turn = 144

output = 1 turn = 145

done in 146 turns

所以我有一个错误。我找不到我的问题。

Answer 1

        if (input % 2 == 0) {
            // transforming a primitive method argument in a function is
            // *NOT* reflected on the variable passed as argument:
            // a call to the function will pass *the value* of the variable 
            // and not the reference to the variable
            input = even(input);
            System.out.println("output = " + input + " turn = " + turn);
        } else if (input % 2 == 1) {
            // see above
            input = odd(input);
            System.out.println("output = " + input + " turn = " + turn);
        }