feat(lc): 每日一题

lc solutions/每日一题/2022-11/24-795-区间子数组的个数.js

@@ -0,0 +1,36 @@
+// 将数组中的数分为三类，0：小于left，1：大于等于left，小于等于right，2：大于right
+// 双指针：计算出1，2的数量减去2
+function numsSubarrayBoundedMax(nums, l, r) {
+  let res = 0,
+    last1 = 0,
+    last2 = 0;
+  for (let i = 0; i < nums.length; i++) {
+    if (nums[i] >= left && nums[i] <= right) {
+      last1 = i;
+    } else if (nums[i] > right) {
+      last2 = i;
+      last1 = -1;
+    }
+
+    if (last1 !== -1) {
+      res += last1 - last2;
+    }
+  }
+  return res;
+}
+
+// 计数：计算出0，1的数量减去0
+function numsSubarrayBoundedMax(nums, l, r) {
+  return count(nums, right) - count(nums, left - 1);
+}
+
+// 返回最大值小于等于lower的子数组数目
+function count(nums, lower) {
+  let res = 0,
+    cur = 0;
+  for (const x of nums) {
+    cur = x < lower ? cur + 1 : 0;
+    res += cur;
+  }
+  return res;
+}