题解 | #未排序数组中累加和为给定值的最长子数组长度#

N,k = map(int,input().split())
arr = list(map(int,input().split()))

sum = 0 
length = 0
tmp_dict = {0:-1}
for i in range(len(arr)):
    sum += arr[i]
    if sum not in tmp_dict:
        tmp_dict[sum] = i
    if sum - k in tmp_dict:
        length = max(length,i-tmp_dict[sum - k])
print(length)