392. Is Subsequence

time: O(n)

space: O(1)

class Solution {
    public boolean isSubsequence(String s, String t) {
        if (s.length() == 0) return true;
        
        int i = 0;
        for (char c : t.toCharArray()) {
            if (c == s.charAt(i)) i++;
            if (i == s.length()) return true;
        }
        return false;
    }
}

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