Is Subsequence

Category

Two Pointers

Checkbox

Difficulty

Easy

Index

Key Ideas

The key idea to solve this problem is to use two pointers to traverse the given strings and check if one is a subsequence of the other.

Problem Number

392

Problem Summary

## Problem Summary: The "Is Subsequence" problem is about determining whether a given string is a subsequence of another given string. A subsequence is formed by deleting some characters from the original string without changing the order of the remaining characters. ## Key Pitfalls: - It is important to note that the characters in the subsequence must maintain their relative order in the original string. - Avoid unnecessary complexity by using a simple approach, such as iterating through both strings simultaneously. - Be cautious of edge cases, such as empty strings or when one of the strings is a subset of the other.

Solution Summary

The best solution to solve the "Is Subsequence" problem from the LeetCode-75 curated list involves using two pointers. We initialize two pointers, one for the given string and another for the subsequence. We iterate through both strings and compare characters at each position. If the characters match, we move both pointers forward. If not, we only move the pointer for the given string. By the end, if the pointer for the subsequence reaches the end, it means that all characters in the subsequence have been found in order in the given string. This solution has a time complexity of O(n), where n is the length of the given string.