Convert Date to Binary

Easy
1772.

Convert Date to Binary

EasyMathStringMicrosoft

Convert Date to Binary is an easy coding problem on strings and math, asked in Microsoft interviews.

You are given a string date in the format yyyy-mm-dd (a valid Gregorian date).

Write the year, the month and the day each in binary, without leading zeros, and join them with - in the same order: year-month-day.

Return that string.

Example 1

Input
date = "2080-02-29"
Output
100000100000-10-11101
Explanation
2080, 2 and 29 in binary are 100000100000, 10 and 11101.

Example 2

Input
date = "1900-01-01"
Output
11101101100-1-1
Explanation
Leading zeros of "01" disappear: 1 is just 1 in binary.

Example 3

Input
date = "2024-12-31"
Output
11111101000-1100-11111

Constraints

  • date.length == 10
  • date[4] == date[7] == '-'
  • every other character of date is a digit
  • date is a valid date between 1900-01-01 and 2100-12-31
Write your solution here. Running it against the tests needs a free account — what you type comes with you.Sign in to run
/**
 * @param {string} date
 * @return {string}
 */
var convertDateToBinary = function(date) {
    // Write your code here
    
};

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Convert Date to Binary — Solution in Python, Java & C++

Convert Date to Binary solution explained: step-by-step approach, complexity and code in Python, Java, C++ and JavaScript. An easy problem.

Convert Date to Binary is an easy coding problem on strings and math, asked in Microsoft interviews.

  • Difficulty: Easy
  • Topics: Strings, Math
  • Asked at: Microsoft
  • Time limit: 2 s
  • Memory limit: 256 MB
  • Languages: JavaScript, TypeScript, Python, Java, C++, C, C#, Go, Kotlin, Swift, Rust, PHP and Ruby

Problem statement

You are given a string date in the format yyyy-mm-dd (a valid Gregorian date).

Write the year, the month and the day each in binary, without leading zeros, and join them with - in the same order: year-month-day.

Return that string.

Example 1

Input: date = "2080-02-29"
Output: 100000100000-10-11101
Explanation: 2080, 2 and 29 in binary are 100000100000, 10 and 11101.

Example 2

Input: date = "1900-01-01"
Output: 11101101100-1-1
Explanation: Leading zeros of "01" disappear: 1 is just 1 in binary.

Example 3

Input: date = "2024-12-31"
Output: 11111101000-1100-11111

Constraints

  • date.length == 10
  • date[4] == date[7] == '-'
  • every other character of date is a digit
  • date is a valid date between 1900-01-01 and 2100-12-31

Hints for Convert Date to Binary

  1. Hint 1

    Split the string on - into three decimal numbers.

  2. Hint 2

    Convert each number to binary — most languages have a built-in, or repeatedly take n % 2 and divide by 2.

  3. Hint 3

    Parsing the number first removes the leading zeros of "01"; join the three binary strings with -.

How to solve Convert Date to Binary

The date's three fields are independent numbers; converting each to base 2 and joining them is the whole task.

Approach

  1. Parse year = date[0..4), month = date[5..7), day = date[8..10) as integers.
  2. Write each in binary with no leading zeros (collect n % 2 while n > 0, then reverse).
  3. Return bin(year) + "-" + bin(month) + "-" + bin(day).

Why it works

Every field is at least 1, so its binary form is non-empty, and converting the parsed integer guarantees there are no leading zeros.

Complexity

  • Time — O(1)
  • Space — O(1)

Pitfalls

  • Converting the text "01" digit by digit would keep a leading zero; parse it as a number first.

Reference solution

Python

def convertDateToBinary(date: str) -> str:
    return "-".join(bin(int(part))[2:] for part in date.split("-"))

Java

public static String convertDateToBinary(String date) {
    String[] parts = date.split("-");
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < parts.length; i++) {
        if (i > 0) sb.append('-');
        sb.append(Integer.toBinaryString(Integer.parseInt(parts[i])));
    }
    return sb.toString();
}

C++

string convertDateToBinary(string date) {
    auto bin = [](int v) {
        string r;
        while (v > 0) { r += (char) ('0' + v % 2); v /= 2; }
        reverse(r.begin(), r.end());
        return r;
    };
    int y = stoi(date.substr(0, 4)), m = stoi(date.substr(5, 2)), d = stoi(date.substr(8, 2));
    return bin(y) + "-" + bin(m) + "-" + bin(d);
}

JavaScript

var convertDateToBinary = function(date) {
    return date.split("-").map(function(p) { return parseInt(p, 10).toString(2); }).join("-");
};

Also on the editorial tab: C, C#, Go, Kotlin, PHP, Ruby, Rust, Swift, TypeScript.

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