Int to Hexadecimal

Solution

Loping through the number

Basic idea

• We can convert a number to hexadecimal by repeatedly dividing the number by 16 and keeping track of the remainders.
• For negative numbers, we can use two's complement representation to convert them to positive numbers before converting them to hexadecimal.

const intToHex = (myInt) => {
    if (myInt === 0) return "0";
    if (myInt < 0) {
        myInt = 0xFFFFFFFF + myInt + 1;
    }
    let hex = "";
    while (myInt > 0) {
        const remainder = myInt % 16;
        hex = (remainder < 10 ? remainder : String.fromCharCode(remainder + 87)) + hex;
        myInt = Math.floor(myInt / 16);
    }
    return hex;
}

Algorithm Detailed Explanation

1. If the input number is 0, return "0".
2. If the input number is negative, convert it to a positive number using two's complement representation.
3. Initialize an empty string hex to store the hexadecimal representation of the number.
4. While the input number is greater than 0, do the following:
   • Calculate the remainder when the number is divided by 16.
   • If the remainder is less than 10, append it to the hex string.
   • If the remainder is greater than or equal to 10, convert it to the corresponding hexadecimal character and append it to the hex string.
   • Update the input number by dividing it by 16 (integer division).
5. Return the hex string as the hexadecimal representation of the input number.

Complexity Analysis

• The time complexity of this solution is O(log(n)), where n is the input number.
• The space complexity is O(log(n)) as well, due to the space used to store the hexadecimal representation.

Built-in Method

const intToHex = (myInt) => {
    return myInt.toString(16);
}

Basic idea

• JavaScript provides a built-in method toString that can be used to convert a number to a string in a specified base.
• We can use this method with a base of 16 to convert a number to its hexadecimal representation.

Complexity Analysis

• The time complexity of this solution is O(1) since it uses a built-in method.
• The space complexity is O(1) as well.