diff --git a/1930. Unique Length-3 Palindromic Subsequences1 b/1930. Unique Length-3 Palindromic Subsequences1 new file mode 100644 index 0000000..c50ecc2 --- /dev/null +++ b/1930. Unique Length-3 Palindromic Subsequences1 @@ -0,0 +1,33 @@ +class Solution { +public: + int countPalindromicSubsequence(string s) { + vectorsubbstr; + vectora(26, 0); + int n = s.size(); + for(int i = 0; i < n; i++){ + if(a[s[i] - 'a'] == 0){ + string sub = s.substr(i, n - i); + subbstr.push_back(sub); + a[s[i] - 'a'] = 1; + } + } + int res = 0; + for(int i = 0; i < subbstr.size(); i++){ + a.clear(); + a.resize(26, 0); + int j = subbstr[i].size() - 1; + while(j > 0 && subbstr[i][j] != subbstr[i][0]){ + j--; + } + j -= 1; + while(j > 0 ){ + if(a[subbstr[i][j] - 'a'] == 0){ + res++; + a[subbstr[i][j] - 'a'] = 1; + } + j--; + } + } + return res; + } +};