Leetcode

Is Subsequence

  • Time:O(n)
  • Space:O(1)

C++

class Solution {
 public:
  bool isSubsequence(string s, string t) {
    if (s.empty())
      return true;

    int i = 0;
    for (const char c : t)
      if (s[i] == c && ++i == s.length())
        return true;

    return false;
  }
};

JAVA

class Solution {
  public boolean isSubsequence(String s, String t) {
    if (s.isEmpty())
      return true;

    int i = 0;
    for (final char c : t.toCharArray())
      if (s.charAt(i) == c && ++i == s.length())
        return true;

    return false;
  }
}