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3557. Find Maximum Number of Non Intersecting Substrings 👍

  • Time: $O(n)$
  • Space: $O(n)$
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class Solution {
 public:
  int maxSubstrings(string word) {
    int ans = 0;
    unordered_map<char, int> firstSeen;

    for (int i = 0; i < word.length(); ++i) {
      const char c = word[i];
      if (!firstSeen.contains(c)) {
        firstSeen[c] = i;
      } else if (i - firstSeen[c] + 1 >= 4) {
        ++ans;
        firstSeen.clear();
      }
    }

    return ans;
  }
};

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class Solution {
  public int maxSubstrings(String word) {
    int ans = 0;
    Map<Character, Integer> firstSeen = new HashMap<>();

    for (int i = 0; i < word.length(); ++i) {
      final char c = word.charAt(i);
      if (!firstSeen.containsKey(c)) {
        firstSeen.put(c, i);
      } else if (i - firstSeen.get(c) + 1 >= 4) {
        ++ans;
        firstSeen.clear();
      }
    }

    return ans;
  }
}

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class Solution:
  def maxSubstrings(self, word: str) -> int:
    ans = 0
    firstSeen = {}

    for i, c in enumerate(word):
      if c not in firstSeen:
        firstSeen[c] = i
      elif i - firstSeen[c] + 1 >= 4:
        ans += 1
        firstSeen.clear()

    return ans