1371 - Find the Longest Substring Containing Vowels in Even Counts

 C++

• class Solution {
  public:
      int findTheLongestSubstring(string s) {
          vector<int> pos(32, INT_MAX);
          pos[0] = -1;
          string vowels = "aeiou";
          int state = 0, ans = 0;
          for (int i = 0; i < s.size(); ++i) {
              for (int j = 0; j < 5; ++j)
                  if (s[i] == vowels[j])
                      state ^= (1 << j);
              ans = max(ans, i - pos[state]);
              pos[state] = min(pos[state], i);
          }
          return ans;
      }
  };

JAVA

• class Solution {
  
      public int findTheLongestSubstring(String s) {
          int[] pos = new int[32];
          Arrays.fill(pos, Integer.MAX_VALUE);
          pos[0] = -1;
          String vowels = "aeiou";
          int state = 0;
          int ans = 0;
          for (int i = 0; i < s.length(); ++i) {
              char c = s.charAt(i);
              for (int j = 0; j < 5; ++j) {
                  if (c == vowels.charAt(j)) {
                      state ^= (1 << j);
                  }
              }
              ans = Math.max(ans, i - pos[state]);
              pos[state] = Math.min(pos[state], i);
          }
          return ans;
      }
  }