2

Author: kedebug

CombinationSum/CombinationSum.cpp

@@ -0,0 +1,42 @@
+class Solution {
+public:
+    vector<vector<int> > combinationSum(vector<int> &candidates, int target) {
+        // Start typing your C/C++ solution below
+        // DO NOT write int main() function
+        
+        combination_set.clear();
+        sort(candidates.begin(), candidates.end());
+        vector<int> nums;
+        DFS(nums, target, candidates, 0);
+        return move(combination_set);
+    }
+    
+    void DFS(vector<int>& nums, int target, vector<int>& candidates, int position) {
+        if (target < 0) return;
+        
+        if (target == 0) {
+            combination_set.push_back(nums);
+            return;
+        }
+        
+        if (position >= candidates.size())
+            return;
+            
+        DFS(nums, target, candidates, position + 1);
+        
+        int value = candidates[position];
+        
+        for (int i = 1; i * value <= target; i++) {
+            for (int j = 0; j < i; j++)
+                nums.push_back(value);
+                
+            DFS(nums, target - i * value, candidates, position + 1);
+            
+            for (int j = 0; j < i; j++)
+                nums.pop_back();
+        }
+    }
+
+private:
+    vector<vector<int>> combination_set;
+};