392. Is Subsequence

Given a string s and a string t , check if s is subsequence of t.

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

Follow up: If there are lots of incoming S, say S1, S2, ... , Sk where k >= 1B, and you want to check one by one to see if T has its subsequence. In this scenario, how would you change your code?

Credits: Special thanks to @pbrother for adding this problem and creating all test cases.

Example 1:

Input: s = "abc", t = "ahbgdc"
Output: true

Example 2:

Input: s = "axc", t = "ahbgdc"
Output: false

Constraints:

• 0 <= s.length <= 100
• 0 <= t.length <= 10^4
• Both strings consists only of lowercase characters.

# @lc code=start
using LeetCode

function is_subsequence(s::String, t::String)::Bool
    if length(s) == 0
        true
    else
        i, j = 1, 1
        while j <= length(t)
            if s[i] == t[j]
                i += 1
                if i > length(s)
                    return true
                end
            end
            j += 1
        end
        false
    end
end
# @lc code=end

is_subsequence (generic function with 1 method)

This page was generated using DemoCards.jl and Literate.jl.