Create 1915.Number-of-Wonderful-Substrings.cpp

Author: wisdompeak

Hash/1915.Number-of-Wonderful-Substrings/1915.Number-of-Wonderful-Substrings.cpp

@@ -0,0 +1,26 @@
+typedef long long ll;
+class Solution {
+public:
+    long long wonderfulSubstrings(string word) 
+    {
+        int n = word.size();
+        int state = 0;
+        vector<int>count(1<<10);
+        count[0]+=1;
+        
+        ll ret = 0;
+        for (int i=0; i<n; i++)
+        {
+            int j = word[i]-'a';
+            state ^= (1<<j);
+            
+            ret += count[state];
+            
+            for (int j=0; j<10; j++)            
+                ret += count[state ^ (1<<j)];                                
+
+            count[state]++;
+        }
+        return ret;
+    }
+};