Create 238-Product-of-Array-Except-Self.java

Author: SharmaTushar1

java/238-Product-of-Array-Except-Self.java

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+//Just store the left and right product (Try doing this with extra space first)
+//This one is constant space because we are returning the array we created
+
+class Solution {
+    public int[] productExceptSelf(int[] nums) {
+        int[] arr = new int[nums.length];
+        arr[0] = 1;
+        for (int i = 1; i<nums.length; i++) {
+            arr[i] = arr[i-1]*nums[i-1];
+        }
+        int prod = nums[nums.length-1];
+        nums[nums.length-1] = 1;
+        for (int i = nums.length-2; i>=0; i--) {
+            int store = nums[i];
+            nums[i] = nums[i+1]*prod;
+            prod = store;
+        }
+        for (int i = 0; i<nums.length; i++) {
+            arr[i] = arr[i]*nums[i];
+        }
+        return arr;
+    }
+}