Problem:
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The Smallest Window I

For a given array $a_1, a_2, a_3, ... , a_N$ of $N$ elements and an integer $S$, find the smallest sub-array size (smallest window length) where the sum of the sub-array is greater than or equal to $S$. If there is not such sub-array, report 0.

Constraints

$1 \leq N \leq 10^5$

$1 \leq S \leq 10^9$

$1 \leq a_i \leq 10^4$

Input

The input is given in the following format.

$N$ $S$

$a_1$ $a_2$ ... $a_N$

Output

Print the smallest sub-array size in a line.

Sample Input 1

6 4
1 2 1 2 3 2

Sample Output 1

2

Sample Input 2

6 6
1 2 1 2 3 2

Sample Output 2

3

Sample Input 3

3 7
1 2 3

Sample Output 3

0

Solution in C++ (judge verdict: Accepted)

#include<bits/stdc++.h>
using namespace std;

int N,S,sum=0,ans=1e9,k;
int a[100000];
int main(){

  scanf("%d %d",&N,&S);
  for(int i=0;i<N;i++){
    scanf("%d",&a[i]);
    sum+=a[i];
    while(sum-a[k]>=S){
      sum-=a[k];
      k++;
    }
    if(sum>=S)ans=min(ans,i-k+1);
  }
  if(ans==1e9)ans=0;
  printf("%d\n",ans);
  return 0;
}