add: ProductArrayWithoutCurrentElement

Author: Jer3myYu

java/Prefix Sums/ProductArrayWithoutCurrentElement.java

@@ -0,0 +1,21 @@
+import java.util.Arrays;
+
+public class ProductArrayWithoutCurrentElement {
+    public int[] productArrayWithoutCurrentElement(int[] nums) {
+        int n = nums.length;
+        int[] res = new int[n];
+        Arrays.fill(res, 1);
+        // Populate the output with the running left product.
+        for (int i = 1; i < n; i++) {
+            res[i] = res[i - 1] * nums[i - 1];
+        }
+        // Multiply the output with the running right product, from right to 
+        // left.
+        int rightProduct = 1;
+        for (int i = n - 1; i > -1; i--) {
+            res[i] *= rightProduct;
+            rightProduct *= nums[i];
+        }
+        return res;
+    }
+}