java学习之—递归

/**
 * 递归
 * Create by Administrator
 * 2018/6/20 0020
 * 上午 9:41
 **/
public class TriangleApp {

    static int theNumber;

    public static void main(String[] args) throws IOException{
        while (true){
            System.out.println("Enter a number:");
            theNumber = getInt();
            int theAnswer = triangle(theNumber);
            System.out.println("Triangle="+theAnswer);
        }
    }

    public static int triangle(int n){
        if(n == 1){
            return 1;
        }else {
            int temp = (n + triangle(n - 1));
            return temp;
        }
    }

    public static int getInt()throws IOException{
        String s = getString();
        return Integer.parseInt(s);
    }

    private static String getString() throws IOException{
        InputStreamReader inputStreamReader = new InputStreamReader(System.in);
        BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
        return bufferedReader.readLine();
    }