10710: ABC130 —— D - Enough Array
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Description
You are given a sequence of positive integers of length $N$, $A=a_1,a_2,…,a_{N}$, and an integer $K$. How many contiguous subsequences of $A$ satisfy the following condition?
- (Condition) The sum of the elements in the contiguous subsequence is at least $K$.
We consider two contiguous subsequences different if they derive from different positions in $A$, even if they are the same in content.
Note that the answer may not fit into a $32$-bit integer type.
- (Condition) The sum of the elements in the contiguous subsequence is at least $K$.
We consider two contiguous subsequences different if they derive from different positions in $A$, even if they are the same in content.
Note that the answer may not fit into a $32$-bit integer type.
Input
Input is given from Standard Input in the following format:
```
$N$ $K$
$a_1$ $a_2$ $...$ $a_N$
```
```
$N$ $K$
$a_1$ $a_2$ $...$ $a_N$
```
Output
Print the number of contiguous subsequences of $A$ that satisfy the condition.
Constraints
- $1 \leq a_i \leq 10^5$
- $1 \leq N \leq 10^5$
- $1 \leq K \leq 10^{10}$
- $1 \leq N \leq 10^5$
- $1 \leq K \leq 10^{10}$
Sample 1 Input
4 10
6 1 2 7
Sample 1 Output
2
The following two contiguous subsequences satisfy the condition:
- $A[1..4]=a_1,a_2,a_3,a_4$, with the sum of $16$
- $A[2..4]=a_2,a_3,a_4$, with the sum of $10$
Sample 2 Input
3 5
3 3 3
Sample 2 Output
3
Note again that we consider two contiguous subsequences different if they derive from different positions, even if they are the same in content.
Sample 3 Input
10 53462
103 35322 232 342 21099 90000 18843 9010 35221 19352
Sample 3 Output
36