codeforces Prison Transfer

Description
The prison of your city has n prisoners. As the prison can’t accommodate all of them, the city mayor has decided to transfer c of the prisoners to a prison located in another city.

For this reason, he made the n prisoners to stand in a line, with a number written on their chests. The number is the severity of the crime he/she has committed. The greater the number, the more severe his/her crime was.

Then, the mayor told you to choose the c prisoners, who will be transferred to the other prison. He also imposed two conditions. They are,

The chosen c prisoners has to form a contiguous segment of prisoners.
Any of the chosen prisoner’s crime level should not be greater then t. Because, that will make the prisoner a severe criminal and the mayor doesn’t want to take the risk of his running away during the transfer.
Find the number of ways you can choose the c prisoners.

Input
The first line of input will contain three space separated integers n (1 ≤ n ≤ 2·105), t (0 ≤ t ≤ 109) and c (1 ≤ c ≤ n). The next line will contain n space separated integers, the ith integer is the severity ith prisoner’s crime. The value of crime severities will be non-negative and will not exceed 109.

Output
Print a single integer — the number of ways you can choose the c prisoners.

Sample Input
Input
4 3 3
2 3 1 1
Output
2
Input
1 1 1
2
Output
0
Input
11 4 2
2 2 0 7 3 2 2 4 9 1 4
Output
6

设置一个b数组来记录之前小于t的个数；

#include <cstdio>#include <cstring>#include <iostream>using namespace std;int a[200001];int b[200001];int main(){    int n,t,c;    while(cin>>n>>t>>c)    {        memset(b,0,sizeof(b));        for(int i=1; i<=n; i++)        {            int x;            cin>>x;            if(x<=t)                           a[i]=1;            b[i]=b[i-1]+a[i];        }        int s=0;        for(int i=1; i+c-1<=n; i++)            if(b[i+c-1]-b[i-1]==c)                s++;        cout<<s<<endl;    }    return 0;}