I have added permutation_of_a_number.cpp code in C++ and CP folder

Author: Pragati Sawaliya

C++/permutaion_of_a_number.cpp

@@ -0,0 +1,21 @@
+class Solution {
+    private:
+   void solve(vector<int>nums,vector<vector<int>>& ans,int index){
+        if(index>=nums.size()){
+            ans.push_back(nums);
+            return;
+        }
+        for(int j=index;j<nums.size();j++){
+            swap(nums[index],nums[j]);
+            solve(nums,ans,index+1);
+            swap(nums[index],nums[j]);
+        }
+    }
+public:
+    vector<vector<int>> permute(vector<int>& nums) {
+        vector<vector<int>> ans;
+        int index=0;
+        solve(nums,ans,index);
+        return ans;
+    }
+};

CP/permutaion_of_a_number.cpp

@@ -0,0 +1,21 @@
+class Solution {
+    private:
+   void solve(vector<int>nums,vector<vector<int>>& ans,int index){
+        if(index>=nums.size()){
+            ans.push_back(nums);
+            return;
+        }
+        for(int j=index;j<nums.size();j++){
+            swap(nums[index],nums[j]);
+            solve(nums,ans,index+1);
+            swap(nums[index],nums[j]);
+        }
+    }
+public:
+    vector<vector<int>> permute(vector<int>& nums) {
+        vector<vector<int>> ans;
+        int index=0;
+        solve(nums,ans,index);
+        return ans;
+    }
+};