Update 1524-number-of-sub-arrays-with-odd-sum.js

Author: everthis

1524-number-of-sub-arrays-with-odd-sum.js

@@ -1,3 +1,29 @@
+/**
+ * @param {number[]} arr
+ * @return {number}
+ */
+const numOfSubarrays = function(arr) {
+  const n = arr.length, mod = 1e9 + 7
+  let sum = 0, res = 0, oddCnt = 0, evenCnt = 0
+  
+  for(let i = 0; i < n; i++) {
+    const cur = arr[i]
+    sum += cur
+    if(sum % 2 === 1) {
+      res++
+      res += evenCnt
+      oddCnt++
+    } else {
+      res += oddCnt
+      evenCnt++
+    }
+  }
+  
+  return res % mod
+};
+
+// another
+
 /**
  * @param {number[]} arr
  * @return {number}