java常见递归练习题

分解成两个子问题,f5(n-1)和f5(n-2)

static int f5(int n){

        if (n == 1 || n == 2){

            return 1;

        }

        return f5(n - 1) + f5(n - 2);

}

static void f7(int[] array,int k){

        if (k == 0){

            return;

        }

        int x = array[k];

        int index = k - 1;

        f7(array,k-1);

        while (x < array[index] && index > -1){

            array[index + 1] = array[index];

            index--;

        }

        array[index + 1] = x;

    }