Create 828.Count-Unique-Characters-of-All-Substrings-of-a-Given-String.cpp

Author: wisdompeak

Hash/828.Count-Unique-Characters-of-All-Substrings-of-a-Given-String/828.Count-Unique-Characters-of-All-Substrings-of-a-Given-String.cpp

@@ -0,0 +1,26 @@
+class Solution {
+    long long M = pow(10,9)+7;
+public:
+    int uniqueLetterString(string S) 
+    {        
+        vector<vector<int>>pos(26);
+        int result=0;
+        for (int i=0; i<S.size(); i++)
+        {
+            pos[S[i]-'A'].push_back(i);
+            for (int i=0; i<26; i++)
+            {
+                if (pos[i].size()==1)
+                    result+=pos[i][0]+1;
+                else if (pos[i].size()>1)
+                {
+                    int k = pos[i].size();
+                    result+=pos[i][k-1]-pos[i][k-2];
+                }
+                result = result%M;    
+            }
+        }
+        return result;
+    }
+    
+};