add: 只出现一次的数字等

src/array/count-number-of-nice-subarrays.js

@@ -0,0 +1,52 @@
+/**
+ * 参考：https://leetcode-cn.com/problems/count-number-of-nice-subarrays/solution/count-number-of-nice-subarrays-by-ikaruga/
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {number}
+ */
+export const numberOfSubarrays = function (nums, k) {
+  const odd = []
+  odd.push(-1)
+
+  let ans = 0
+  let i = 1
+  for (let j = 0; j <= nums.length; j++) {
+    if (j === nums.length || (nums[j] & 1)) {
+      odd.push(j)
+    }
+
+    if (odd.length - i > k) {
+      const left = odd[i] - odd[i - 1]
+      const right = j - odd[odd.length - 2]
+      ans += left * right
+      i++
+    }
+  }
+  return ans
+}
+
+/**
+ * 错误解法
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {number}
+ */
+// export const numberOfSubarrays = function (nums, k) {
+//   let res = 0
+//   for (let n = 0, len = nums.length; n < len; n++) {
+//     let num = 0
+//     let i = n
+//     while (num < k && i < len) {
+//       if (nums[i] % 2 !== 0) {
+//         num++
+//       }
+//       i++
+//     }
+
+//     if (num === k) {
+//       res++
+//     }
+//   }
+
+//   return res
+// }