✨ sum of all odd length subarrays

Author: tangweikun

src/1588-sum-of-all-odd-length-subarrays/index.js

@@ -0,0 +1,19 @@
+/**
+ * @desc 给你一个正整数数组 arr ，请你计算所有可能的奇数长度子数组的和。
+ * @param {number[]} arr
+ * @return {number}
+ */
+var sumOddLengthSubarrays = function (arr) {
+  let res = 0;
+
+  for (let i = 0; i < arr.length; i++) {
+    let len = 0;
+    let cache = 0;
+    for (let j = i; j < arr.length; j++) {
+      cache += arr[j];
+      ++len % 2 && (res += cache);
+    }
+  }
+
+  return res;
+};