Reverse Interger

Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1], then return 0.
Example 1:
Input: x = 123
Output: 321

First try

x % 10
didn’t have a solution

Refer to others’ solution

we can use number.toString()
array.split(“”)
array.reverse()
array.join(“”)

Math.pow(2,n) represents 2[^n]
Math.abs()return absolute value

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

/**
 * @param {number} x
 * @return {number}
 */
var reverse = function(x) {
    const isNegtive = x<0
    const strArray = Math.abs(x).toString().split("")
    const num = strArray.reverse().join("")
    if ((isNegtive && (num>Math.pow(2,31))) || (!isNegtive && (num>Math.pow(2,31)-1))){
        return 0;
    }else{
        if(isNegtive){
            return -num;
        }else{
            return num;
        }
    }
};

Runtime: 88 ms, faster than 74.47% of JavaScript online submissions for Reverse Integer.
Memory Usage: 40.3 MB, less than 70.81% of JavaScript online submissions for Reverse Integer.

• ← Previous Post
• Next Post →