2540. Minimum Common Value

Description

Given two integer arrays nums1 and nums2, sorted in non-decreasing order, return the minimum integer common to both arrays. If there is no common integer amongst nums1 and nums2, return -1.

Note that an integer is said to be common to nums1 and nums2 if both arrays have at least one occurrence of that integer.

 

Example 1:

Input: nums1 = [1,2,3], nums2 = [2,4]
Output: 2
Explanation: The smallest element common to both arrays is 2, so we return 2.

Example 2:

Input: nums1 = [1,2,3,6], nums2 = [2,3,4,5]
Output: 2
Explanation: There are two common elements in the array 2 and 3 out of which 2 is the smallest, so 2 is returned.

 

Constraints:

• 1 <= nums1.length, nums2.length <= 105
• 1 <= nums1[i], nums2[j] <= 109
• Both nums1 and nums2 are sorted in non-decreasing order.

 

Solutions

Solution: Two Pointers

• Time complexity: O(m+n)
• Space complexity: O(1)

 

JavaScript

/**
 * @param {number[]} nums1
 * @param {number[]} nums2
 * @return {number}
 */
const getCommon = function (nums1, nums2) {
  const m = nums1.length;
  const n = nums2.length;
  let pos = 0;

  for (let index = 0; index < n; index++) {
    const num2 = nums2[index];

    while (pos < m && nums1[pos] < num2) {
      pos += 1;
    }

    if (nums1[pos] === num2) {
      return num2;
    }
  }

  return -1;
};