/**
 * Given two strings s and t, return true if s is a subsequence of t, or false otherwise.
 *
 * 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).
 *
 *
 *
 * 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
 * s and t consist only of lowercase English letters.
 *
 *
 * Follow up: Suppose there are lots of incoming s, say s1, s2, ..., sk where k >= 10^9,
 * and you want to check one by one to see if t has its subsequence.
 * In this scenario, how would you change your code?
 * @see <a href="https://leetcode.com/problems/is-subsequence/">LeetCode</a>
 */
fun isSubsequence(s: String, t: String): Boolean {
    var sIndex = 0
    var tIndex = 0
    while (sIndex < s.length && tIndex < t.length) {
        if (s[sIndex] == t[tIndex]) {
            sIndex++
        }
        tIndex++
    }
    return sIndex == s.length
}

/**
 * Given two strings s and t, return true if s is a subsequence of t, or false otherwise.
 *
 * 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).
 *
 *
 *
 * 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
 * s and t consist only of lowercase English letters.
 *
 *
 * Follow up: Suppose there are lots of incoming s, say s1, s2, ..., sk where k >= 10^9,
 * and you want to check one by one to see if t has its subsequence.
 * In this scenario, how would you change your code?
 * @see <a href="https://leetcode.com/problems/is-subsequence/">LeetCode</a>
 */
fun isSubsequence(s: String, t: String): Boolean {
    var sIndex = 0
    var tIndex = 0
    while (sIndex < s.length && tIndex < t.length) {
        if (s[sIndex] == t[tIndex]) {
            sIndex++
        }
        tIndex++
    }
    return sIndex == s.length
}
