编写递归函数 [英] Writing recursive functions

问题描述

我在编写递归函数时遇到麻烦。

I'm having trouble with writing recursive functions.

三角数如下：

1 = 1

3 = 1 + 2

3 = 1 + 2

6 = 1 + 2 + 3

6 = 1 + 2 + 3

10 = 1 + 2 + 3 + 4

10 = 1 + 2 + 3 + 4

15 = 1 + 2 + 3 + 4 + 5

15 = 1 + 2 + 3 + 4 + 5

21 = 1 + 2 + 3 + 4 + 5 + 6

21 = 1 + 2 + 3 + 4 + 5 + 6

等。

该系列以1（第一个三角数）开头。为了计算第n个三角数，n为
加到前一个三角数上。例如，通过将第三个三角数加4（即6）来计算第四个三角数
，即10 =（1 + 2 + 3）+ 4。

The series begins with 1 (the first triangular number). To calculate the nth triangular number, n is added to the previous triangular number. For example, the fourth triangular number is calculated by adding 4 to the third triangular number (which is 6), i.e. 10 = (1 + 2 + 3) + 4.

到目前为止，这是我想出的：

So far, this is what I've come up with:

int triNum(n)
{
    if (n<=1)
        return n;

    int num = 0;

    for (int i = 0; i < n; i++)
    {
        num = n + triNum(n-1)
    }
    return num;
}

但是我不确定这是否是正确的答案，任何人都可以帮忙指导我如何解决此问题？

However I'm not sure that this is the correct answer, can anyone help guide me how I should approach this problem?

推荐答案

这会产生所需的输出：

int tri(int n) {
    if (n < 1) return 1;
    return (n+1) + tri(n-1);
}

您可以像这样测试它：

int main(void){
    for (int i=0; i<10; i++) {
        printf("%d: %d\n",i,tri(i));
    }
    return 0;
}

这篇关于编写递归函数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！