/** * 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(); }