java杨辉三角递归实现_JAVA_编程开发_程序员俱乐部

转载请注明出处：http://shuiguaiqq.iteye.com/blog/2065671

网上看到的几乎都是大同小异，而本人喜欢逻辑清晰的代码，忍不住动手写了下，代码如下：

class="java" name="code">public class YangHui {
    public static void main(String[] args) {
        int n = 9;
        displayYangHui(n);
    }

    public static void displayYangHui(int n) {
        for (int i = n - 1; i >= 0; i--) {
            for (int j = 0; j < i; j++) {
                System.out.print(" ");
            }
            showRow(getRow(n - i));
        }
    }

    private static void showRow(int[] row) {
        for (int i = 0; i < row.length; i++) {
            System.out.print(row[i] + " ");
        }
        System.out.println();
    }

    private static int[] getRow(int row) {
        if (row == 1) {
            return new int[] { 1 };
        }
        if (row == 2) {
            return new int[] { 1, 1 };
        }

        int[] result = new int[row];
        for (int i = 0; i < result.length; i++) {
            if (i == 0 || i == result.length - 1) {
                result[i] = 1;
            } else {
                result[i] = getRow(row - 1)[i - 1] + getRow(row - 1)[i];
            }
        }
        return result;
    }

}

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