feat(leetcode/238): Product of Array Except Self (Medium)

Author: renovizee

product-of-array-except-self/renovizee.java

@@ -2,14 +2,45 @@
 
 // tag renovizee 2week
 // https://github.com/DaleStudy/leetcode-study/issues/239
-// https://leetcode.com/problems/product-of-array-except-self/
+// https://leetcode.com/problems/product-of-array-except-self/  #238 #Medium
 class Solution {
     // Solv1 :
     // 시간복잡도 : O(n)
     // 공간복잡도 : O(n)
     public int[] productExceptSelf(int[] nums) {
 
+        boolean isZero = false;
+        int zeroIndex = 0;
+
+        int productExceptZero = 1;
+        for (int i = 0; i < nums.length; i++) {
+            if (nums[i] == 0) {
+                if (isZero) { // zero가 2개면 모든 원소가 0임.
+                    return new int[nums.length];
+                }
+                zeroIndex = i;
+                isZero = true;
+            } else {
+                productExceptZero *= nums[i];
+            }
+        }
+
+        int[] result = new int[nums.length];
+        for (int i = 0; i < nums.length; i++) {
+            if (isZero) {
+                if (i != zeroIndex) {
+                    result[i] = 0;
+                } else {
+                    result[i] = productExceptZero;
+                }
+            } else {
+                result[i] = productExceptZero / nums[i];
+            }
+
+        }
+        return result;
     }
+
 }
 
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