product-of-array-except-self

Author: changhyumm

product-of-array-except-self/changhyumm.py

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+class Solution:
+    def productExceptSelf(self, nums: List[int]) -> List[int]:
+        # ans = [1] * len(nums)
+        # for i in range(len(nums)):
+        #     for j in range(len(nums)):
+        #         if i != j:
+        #             ans[i] = ans[i] * nums[j]
+        # return ans
+        # 시간복잡도를 줄이기 위해서 이중루프를 안쓰는 방법으로
+        left = [1] * len(nums)
+        right = [1] * len(nums)
+        for i in range(len(nums) - 1):
+            left[i+1] = left[i] * nums[i]
+        print(left)
+        for j in range(len(nums) - 1, 0, -1):
+            right[j-1] = right[j] * nums[j]
+        print(right)
+        
+        answer = []
+        for k in range(len(left)):
+            answer.append(left[k]*right[k])
+        return answer