Create remove_all_adjacent_from_string_ii.cpp

Author: avidLearnerInProgress

remove_all_adjacent_from_string_ii.cpp

@@ -0,0 +1,48 @@
+class Solution {
+private:
+    void removeHelper(string &s, int K) {
+        int n = s.length();
+        if(n < K ) return; // edgecase
+		// cout<<"\nCurrent string - "<<s<<"\n";
+		
+		bool remove = false;
+        int position = 0;
+        int start = 0;
+        
+        while(position <= n-K+1) {
+            if(s[position] == s[position+1]) { // if two characters match, then check for the next K characters
+                start = position; // initialize start pointer for removal
+                // cout<<"Start"<<start<<"\t";
+                int checkEqual = 1; // to check for K matches, the count of equal matches must be K - 1. Thus, 1 + K - 1 = K.
+                while(s[position] == s[position+1]) { // if all the next K characters match
+                    ++position, ++checkEqual;
+                    if(checkEqual == K) break; 
+                }
+                // cout<<"CheckEqual"<<checkEqual<<"\n";
+                if(checkEqual == K and start <= n-K) {
+                    remove = true; // flag for recursive call
+                    s.erase(s.begin() + start, s.begin() + start + K);
+                    cout<<s<<" |##| "<<remove<<" | ";
+                    position += K;
+                    if(position == n) { // check for out of bounds
+                        // cout<<"1\n";
+                        break;
+                    }
+                    else
+                        // cout<<"0\n";
+                }
+            }
+            else {
+                ++position; //increment and check next char in case of mismatch
+            }
+        }
+        if(remove == false) return; //if no duplicate found or if string has become empty after recursive deletions
+        else if(remove == true) removeHelper(s, K);
+    }
+public:
+    string removeDuplicates(string S, int k) {
+        if(S == "") return "";
+        removeHelper(S, k);
+        return S;   
+    }  
+};