Create 966. Vowel Spellchecker (#885)

Author: Chayandas07

966. Vowel Spellchecker

@@ -0,0 +1,86 @@
+class Solution {
+public:
+    bool cons(char c) //returns true if character is a non-vowel
+    {
+        if(c!='a' && c!='e' && c!='i' && c!='o' && c!='u')
+            return true;
+        return false;
+    }
+    string modify(string s)
+    {
+        string ans="";
+        for(int i=0;i<=s.size();i++)
+        {
+            if(s[i]=='a' || s[i]=='e' || s[i]=='i' || s[i]=='o' || s[i]=='u'){
+                ans+="$";
+            }else{
+                ans+=s[i];
+            }
+        }
+        return ans;
+    }
+    vector<string> spellchecker(vector<string>& wordlist, vector<string>& queries) {
+        
+        int n = wordlist.size();
+        
+        map<string,int> mp_exact;
+        map<string,int> mp_lower;
+        map<string,int> mp_modified;
+        vector<string> lower(n);
+        for(int i=0;i< n;i++)
+        {
+            string s = wordlist[i];
+            mp_exact[s]=i+1;
+
+            //mp_exact hashmap will store index+1 of occurence of word from wordList
+
+            transform(s.begin(),s.end(),s.begin(),::tolower);
+            lower[i]=s;
+            if(!mp_lower[s]){
+                mp_lower[s]=i+1; //we store index+1 
+            }
+            
+            string modified = modify(s);
+            if(!mp_modified[modified]){
+                mp_modified[modified]=i+1;
+            }
+        
+        }
+
+        int m = queries.size();
+        vector<string> ans;
+        for(int i=0;i<m;i++)
+        {
+            string q = queries[i];
+            if(mp_exact[q]){ // when we get exact match
+                ans.push_back(q); 
+            }else{
+                transform(q.begin(),q.end(),q.begin(),::tolower);
+                //we have converted query to all lower now
+
+                if(mp_lower[q]) //after converting query to lower and checking in lower map if we get match
+                {
+                    int ind = mp_lower[q]-1;
+                    ans.push_back(wordlist[ind]);
+                }else{  
+                    //now we check for vowel mismatch case
+
+                    string q_mod = modify(q);
+                    //modified query such that all vowels are $ -> only non-vowel remain
+
+                    if(mp_modified[q_mod])
+                    {
+                        int ind = mp_modified[q_mod]-1;
+                        ans.push_back(wordlist[ind]);
+                    }else{
+                        ans.push_back("");
+                    }
+                }
+            }
+        }
+
+        return ans;
+
+        
+    }
+};