combination sum 2

Author: sachuverma

Striver Sheet/Day-9/Combination Sum II.cpp

@@ -0,0 +1,65 @@
+/*
+Combination Sum II
+==================
+
+Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sum to target.
+
+Each number in candidates may only be used once in the combination.
+
+Note: The solution set must not contain duplicate combinations.
+
+Example 1:
+Input: candidates = [10,1,2,7,6,1,5], target = 8
+Output: 
+[
+[1,1,6],
+[1,2,5],
+[1,7],
+[2,6]
+]
+
+Example 2:
+Input: candidates = [2,5,2,1,2], target = 5
+Output: 
+[
+[1,2,2],
+[5]
+]
+
+Constraints:
+1 <= candidates.length <= 100
+1 <= candidates[i] <= 50
+1 <= target <= 30
+*/
+
+class Solution
+{
+public:
+  void dfs(vector<int> &arr, int i, int tar, vector<int> atn, vector<vector<int>> &ans)
+  {
+    if (tar < 0)
+      return;
+    if (tar == 0)
+    {
+      ans.push_back(atn);
+      return;
+    }
+
+    for (int j = i; j < arr.size(); ++j)
+    {
+      if (j != i && arr[j] == arr[j - 1])
+        continue;
+      atn.push_back(arr[j]);
+      dfs(arr, j + 1, tar - arr[j], atn, ans);
+      atn.pop_back();
+    }
+  }
+
+  vector<vector<int>> combinationSum2(vector<int> &arr, int target)
+  {
+    vector<vector<int>> ans;
+    sort(arr.begin(), arr.end());
+    dfs(arr, 0, target, {}, ans);
+    return ans;
+  }
+};

Striver Sheet/README.md

@@ -78,7 +78,7 @@
 - [Subset Sums](https://practice.geeksforgeeks.org/problems/subset-sums2234/1#) - [Cpp Soultion](./Day-9/Subset%20Sums.cpp)
 - [Subsets II](https://leetcode.com/problems/subsets-ii/) - [Cpp Soultion](./Day-9/Subsets%20II.cpp)
 - [Combination Sum](https://leetcode.com/problems/combination-sum/) - [Cpp Soultion](./Day-9/Combination%20Sum.cpp)
-- []() - [Cpp Soultion](./Day-9/.cpp)
+- [Combination Sum II](https://leetcode.com/problems/combination-sum-ii/) - [Cpp Soultion](./Day-9/Combination%20Sum%20II.cpp)
 - []() - [Cpp Soultion](./Day-9/.cpp)
 - []() - [Cpp Soultion](./Day-9/.cpp)