题解 | #最大值减去最小值小于或等于num的子数组数量#

n, num = map(int, input().split())
nums = list(map(int, input().split()))
import collections
q_max = collections.deque()
q_min = collections.deque()
i, j, res = 0, 0, 0
while i < n:
    while j < n:
        while not q_min or q_min[-1] != j:
            while q_max and nums[q_max[-1]] < nums[j]:
                q_max.pop()
            q_max.append(j)
            while q_min and nums[q_min[-1]] > nums[j]:
                q_min.pop()
            q_min.append(j)
        if nums[q_max[0]] - nums[q_min[0]] > num:
            break
        j += 1
    res += j - i
    if q_max[0] == i:
        q_max.popleft()
    if q_min[0] == i:
        q_min.popleft()
    i += 1
print(res)