二分法计算根号2

@Test
	public void Sprt2() {
		double num = 2 ;
		double left = 0 ;
		double right = num ;
		double ans = SprtFunction1(left , right , num) ;
		System.out.println(ans);
	}
	
   /**
    * 迭代
    */
	public double SprtFunction1(double left , double right , double target) {
		double mid = (left + right) / 2 ;
		while(mid - left > 0.001) {
			if (mid * mid > target) {
				right = mid ;
			}else {
				left = mid ;
			}
			mid = (left + right) / 2 ;
		}
		return mid ;
	}
	
	/**
	 * 递归
	 */	
	public double SprtFunction2(double left , double right , double target) {
		double mid = (left + right) / 2 ;
		if(mid - left < 0.001) {
			return mid ;
		}
		if (mid * mid > target) {
			return SprtFunction2(left , mid , target) ;
		} else {
			return SprtFunction2(mid , right , target) ;
		}
	}