problems-amit-kumar-biswas.ts

// problem 1
function isPalindrome(x: number): boolean {
  const xStr = x.toString();

  for (let index = 0; index < xStr.length / 2; index++) {
    const leftIndex = index;
    const rightIndex = xStr.length - index - 1;

    if (leftIndex === rightIndex) return true;
    if (xStr[leftIndex] !== xStr[rightIndex]) return false;
  }
  return true;
}

// console.log(isPalindrome(121));
// console.log(isPalindrome(-121));
// console.log(isPalindrome(10));

// problem 3
function reverseDigit(given: number) {
  const reverseStr = given.toString().split("").reverse().join("");
  let zeroEndsAt = -999;

  for (let index = 0; index < reverseStr.length; index++) {
    if (parseInt(reverseStr[index]) > 0) {
      zeroEndsAt = index;
      break;
    }
  }
  return parseInt(reverseStr.split("").slice(zeroEndsAt).join(""));
}

function distinctPositive(arr: number[]): number {
  const result = [...arr];

  for (const num of arr) {
    result.push(reverseDigit(num));
  }

  const distinct = {};
  for (const num of result) {
    if (distinct[num]) continue;
    distinct[num] = true;
  }

  return Object.keys(distinct).length;
}

// console.log(distinctPositive([1, 13, 10, 12, 31]));
// console.log(distinctPositive([13, 13, 12, 12, 31]));
// console.log(distinctPositive([2, 2, 2]));

// problem 2
function distinctTriplets(arr: number[]) {
  const triplets: number[][] = [];

  for (let i = 0; i < arr.length; i++) {
    for (let j = 0; j < arr.length; j++) {
      for (let k = 0; k < arr.length; k++) {
        if (i != j && j != k && i != k && arr[i] + arr[j] + arr[k] === 0) {
          triplets.push([arr[i], arr[j], arr[k]]);
        }
      }
    }
  }
  // some function to find distinct triplets to find in triplets array
  // hashmap or set can be used
  const map = {};
  for (const triplet of triplets) {
    console.log(triplet);
  }
  return triplets;
}