求字段和问题

[damotiansheng]

Petr is a Bachelor of Mathematics. He is about to graduate, and need to finish a graduation design. His design is about sum of an array. He is given an array of positive numbers, and a number M. He is asked to find out how many sub-array have a sum that is less than M.

Input

There are several cases in the input. For each case, first given a number n, which tells how many numbers are there in the array, and a M, followed by n numbers.
n will be positive and no larger than 20000,while M less than 400000000,your given numbers in the array will be no larger than 20000. n=0 and M=0 terminates the input.

Output

Output the answer for each case, one in a line.

Sample Input

5 7
1 1 4 5 2
2 100
10 9
0 0

Sample Output

8
3


请问有什么比较好的算法不，要求其复杂度低于O(n^2)，不然超时了，不使用2层遍历

[凡心未灭]

可以先对输入数据进行排序，
比如，如果input[0] + input[2]>=M,后面input[0] + input[3]的就不需要比较了.虽然还是二层遍历，不过比较次数会少一点，在加上排序所用时间……难说，LZ试一下