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You are given two strings s and t.

You are allowed to remove any number of characters from the string t.

The score string is 0 if no characters are removed from the string t, otherwise:

Let left be the minimum index among all removed characters.

Let right be the maximum index among all removed characters.

Then the score of the string is right - left + 1.

Return the minimum possible score to make t a subsequence of s.

A subsequence of a string is a new string that is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (i.e., “ace” is a subsequence of “abcde” while “aec” is not).

[LeetCode] Substring XOR Queries 2023-02-12|PSLeetCode|Problem Solving-Bit Manipulation-Sliding Window

2564. Substring XOR Queries

You are given a binary string s, and a 2D integer array queries where queries[i] = [firsti, secondi].

For the ith query, find the shortest substring of s whose decimal value, val, yields secondi when bitwise XORed with firsti. In other words, val ^ firsti == secondi.

The answer to the ith query is the endpoints (0-indexed) of the substring [lefti, righti] or [-1, -1] if no such substring exists. If there are multiple answers, choose the one with the minimum lefti.

Return an array ans where ans[i] = [lefti, righti] is the answer to the ith query.

A substring is a contiguous non-empty sequence of characters within a string.

[LeetCode] Count the Number of Fair Pairs 2023-02-12|PSLeetCode|Problem Solving-Binary Search

2563. Count the Number of Fair Pairs

Given a 0-indexed integer array nums of size n and two integers lower and upper, return the number of fair pairs.

A pair (i, j) is fair if:

0 <= i < j < n, and

lower <= nums[i] + nums[j] <= upper

[LeetCode] Find the Array Concatenation Value 2023-02-12|PSLeetCode|Problem Solving-Two Pointer

2562. Find the Array Concatenation Value

You are given a 0-indexed integer array nums.

The concatenation of two numbers is the number formed by concatenating their numerals.

For example, the concatenation of 15, 49 is 1549.

The concatenation value of nums is initially equal to 0. Perform this operation until nums becomes empty:

If there exists more than one number in nums, pick the first element and last element in nums respectively and add the value of their concatenation to the concatenation value of nums, then delete the first and last element from nums.

If one element exists, add its value to the concatenation value of nums, then delete it.

Return the concatenation value of the nums.