diff --git "a/\347\253\266\346\212\200\343\203\227\343\203\255\345\260\261\346\264\273\351\203\250PR\347\224\250/39. Combination Sum" "b/\347\253\266\346\212\200\343\203\227\343\203\255\345\260\261\346\264\273\351\203\250PR\347\224\250/39. Combination Sum"
new file mode 100644
index 0000000..b3be849
--- /dev/null
+++ "b/\347\253\266\346\212\200\343\203\227\343\203\255\345\260\261\346\264\273\351\203\250PR\347\224\250/39. Combination Sum"	
@@ -0,0 +1,27 @@
+``` python 
+3回目
+# 時間計算量: O(2^N)
+# 空間計算量: O(N)
+N = len(candidates)
+
+class Solution:
+    def combinationSum(self, candidates: List[int], target: int) -> List[List[int]]:
+        
+        all_valid_combination = []
+
+        def find_vaild_combination(index, current_target, current_combination):
+            if len(candidates) <= index:
+                if  current_target == 0:
+                    all_valid_combination.append(current_combination[:])
+                return
+
+            if  candidates[index] <= current_target:
+                current_combination.append(candidates[index])
+                find_vaild_combination(index, current_target-candidates[index], current_combination)
+                current_combination.pop()
+
+            find_vaild_combination(index+1, current_target, current_combination)
+
+        find_vaild_combination(0, target, [])
+        return all_valid_combination
+```
diff --git "a/\347\253\266\346\212\200\343\203\227\343\203\255\345\260\261\346\264\273\351\203\250PR\347\224\250/39.-Combination-Sum 4th.md" "b/\347\253\266\346\212\200\343\203\227\343\203\255\345\260\261\346\264\273\351\203\250PR\347\224\250/39.-Combination-Sum 4th.md"
new file mode 100644
index 0000000..c98a303
--- /dev/null
+++ "b/\347\253\266\346\212\200\343\203\227\343\203\255\345\260\261\346\264\273\351\203\250PR\347\224\250/39.-Combination-Sum 4th.md"	
@@ -0,0 +1,24 @@
+### 時間: 3m51s
+### Error: 0
+### 時間計算量: O(len(candidates)^(target/min(candidates) + 1))
+### 空間計算量: O(target/min(candidates) + space for Answer)
+```
+class Solution:
+    def combinationSum(self, candidates: List[int], target: int) -> List[List[int]]:
+        result = []
+        combination = []
+
+        def find_all_combiantions(index, current_target, combination):
+            if index == len(candidates):
+                if current_target == 0:
+                    result.append(combination)
+                return
+
+            if candidates[index] <= current_target:
+                find_all_combiantions(index, current_target - candidates[index], combination + [candidates[index]])
+
+            find_all_combiantions(index + 1, current_target, combination)
+
+        find_all_combiantions(0, target, [])
+        return result
+```