Create permutations-ii.cpp

Author: avidLearnerInProgress

permutations-ii.cpp

@@ -0,0 +1,37 @@
+class Solution {
+    
+private:
+        void backtrack(vector<vector<int>> &global_result, vector<int> &local_result, vector<int> &nums, vector<bool> &visited) {
+            
+            if(local_result.size() == nums.size()) {
+                global_result.push_back(local_result);
+            } 
+            
+            for(int i=0; i<nums.size(); i++) {
+            
+                if(visited[i] or (i > 0 and nums[i] == nums[i-1] and visited[i-1])) continue;
+                
+                local_result.push_back(nums[i]); 
+                visited[i] = true;
+                
+                backtrack(global_result, local_result, nums, visited);
+                
+                local_result.pop_back();
+                visited[i] = false;
+                
+            }
+            
+        }
+    
+    
+public:
+    vector<vector<int>> permuteUnique(vector<int>& nums) {
+            if(nums.size() == 0) return vector<vector<int>>();
+            vector<vector<int>> gr;
+            vector<int> lr;
+            vector<bool> visited(nums.size(), false);
+            sort(nums.begin(), nums.end());
+            backtrack(gr, lr, nums, visited);
+            return gr;    
+    }
+};