solve product of array except self

Author: JangAyeon

product-of-array-except-self/JangAyeon.js

@@ -0,0 +1,29 @@
+/**
+ * @param {number[]} nums
+ * @return {number[]}
+ */
+var productExceptSelf = function (nums) {
+  let answer = [];
+
+  const p = [];
+  for (let i = 0; i < nums.length; i++) {
+    if (i == 0) {
+      const n = nums.slice(i + 1).reduce((acc, curr) => (acc *= curr), 1);
+      console.log(n);
+      p.push([1, n]);
+      answer.push(1 * n);
+    } else {
+      const [left, right] = p[i - 1];
+      if (nums[i] === 0) {
+        const n = nums.slice(i + 1).reduce((acc, curr) => (acc *= curr), 1);
+        p.push([left * nums[i - 1], n]);
+        answer.push(left * nums[i - 1] * n);
+      } else {
+        p.push([left * nums[i - 1], right / nums[i]]);
+        answer.push((left * nums[i - 1] * right) / nums[i]);
+      }
+    }
+  }
+
+  return answer;
+};