js算法--递归相关

一、二进制转换

通过某个递归函数将输入的数字转化为二进制字符串

console.log(decimalToBinary(3)); // 11
console.log(decimalToBinary(8)); // 1000
console.log(decimalToBinary(1000)); // 1111101000

function decimalToBinary(digit) {
     
	if (digit >= 1) {
     
		if (digit % 2) {
     
			//不能被2整除
			return decimalToBinary((digit - 1) / 2) + 1;
		} else {
     
			return decimalToBinary(digit / 2) + 0;
		}
	} else {
     
		return '';
	}
}

二、二分搜索

const arr = [1,2,3,4,5,6,7,8,9];
console.log(recursiveBinarySearch(arr,8,arr[0],arr.length-1)) ;
function recursiveBinarySearch(array, value, leftPosition, rightPosition) {
     
	if (leftPosition > rightPosition) return -1;

	var middlePivot = Math.floor((leftPosition + rightPosition) / 2);
	if (array[middlePivot] === value) {
     
		return middlePivot;
	} else if (array[middlePivot] > value) {
     
		return recursiveBinarySearch(array, value, leftPosition, middlePivot - 1);
	} else {
     
		return recursiveBinarySearch(array, value, middlePivot + 1, rightPosition);
	}
}

参考至https://mp.weixin.qq.com/s/mZBallPBShXhRHHXqyWnig