DEV Community: Himanshu Joshi

How Much is True?

Himanshu Joshi — Fri, 07 Feb 2025 07:44:34 +0000

Create a function which returns the number of *true * values there are in an array.

Examples
countTrue([true, false, false, true, false]) ➞ 2

countTrue([false, false, false, false]) ➞ 0

countTrue([]) ➞ 0

Notes
Return 0 if given an empty array.
All array items are of the type bool (true or false).

function countTrue(array){
   if(array.length==0){
       return 0;
   }
 return array.filter((val)=>(val==true)).length;
}
console.log(countTrue([true, false, false, true, false]));
console.log(countTrue([false, false, false, false]));
console.log(countTrue([]));

Tile Teamwork Tactics

Himanshu Joshi — Fri, 07 Feb 2025 07:10:06 +0000

In a board game, a piece may advance 1-6 tiles forward depending on the number rolled on a six-sided die. If you advance your piece onto the same tile as another player's piece, both of you earn a bonus.

Can you reach your friend's tile number in the next roll? Create a function that takes your position a and your friend's position b and returns a boolean representation of whether it's possible to earn a bonus on any die roll.

Examples

possibleBonus(3, 7) ➞ true

possibleBonus(1, 9) ➞ false

possibleBonus(5, 3) ➞ false

function possibleBonus(a, b) {
    if (a >= b) {
        return false;
    }
    let result = b - a;
    return result <= 6;
}
console.log(possibleBonus(3, 6)); // true

DSA Problem #1 Determine If Two Numbers Add up to a Target Value (PHP)

Himanshu Joshi — Wed, 05 Feb 2025 06:42:52 +0000

Given two unique integer arrays $a and $b, and an integer target value $v, create a function to determine whether there is a pair of numbers that add up to the target value $v, where one number comes from one array $a and the other comes from the second array $b. Return true if there is a pair that adds up to the target value; otherwise, return false.

Examples

sumOfTwo([1, 2], [4, 5, 6], 5) ➞ true

sumOfTwo([1, 2], [4, 5, 6], 8) ➞ true

sumOfTwo([1, 2], [4, 5, 6], 3) ➞ false

sumOfTwo([1, 2], [4, 5, 6], 9) ➞ false

<?php 
function sumOfTwo($arr1, $arr2, $element) {
    // Convert arr1 into a hash set for quick lookups
    $set = array_flip($arr1);  // array_flip converts values into keys

    foreach ($arr2 as $val) {
        $complement = $element - $val;
        if (isset($set[$complement])) {  // Faster lookup
            return true;  // Return immediately if found
        }
    }
    return false;
}

// Test cases
echo  (sumOfTwo([1, 2], [4, 5, 6], 5) ? "true" : "false");
echo (sumOfTwo([1, 2], [4, 5, 6], 8) ? "true" : "false");
echo (sumOfTwo([1, 2], [4, 5, 6], 3) ? "true" : "false");
echo (sumOfTwo([1, 2], [4, 5, 6], 9) ? "true" : "false");
?>