Prison Transfer (Codeforces 427B)
Tags: Implement, data structures

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 Inputs:
4 3 3
2 3 1 1

1 1 1
2

11 4 2
2 2 0 7 3 2 2 4 9 1 4

Sample Outputs:
2

0

6

Solution (Python):
def ways(n, t, c, prisoners):
    valid = 0
    ways = 0
    if n < c:
        return 0
    for p in prisoners:
        if p <= t:
            valid += 1
        else:
            valid = 0
        if c <= valid:
            ways += 1
    return ways
(n, t, c) = map(int, input().split())
prisoners = map(int, input().split())
print(ways(n, t, c, prisoners))

Solution (Python):
def get_number_of_valid_segments(stream, crime_level_limit, segment_length):
    """"""
    current_segment_length = 0
    valid_segments = 0
    for crime_level in stream:
        if crime_level <= crime_level_limit:
            current_segment_length += 1
        else:
            current_segment_length = 0
        if current_segment_length >= segment_length:
            valid_segments += 1
    return valid_segments
(num_prisoners, crime_level_limit, segment_length) = map(int, input().split())
crime_levels = map(int, (num for num in input().split()))
num_valid_segments = get_number_of_valid_segments(crime_levels, crime_level_limit, segment_length)
print(num_valid_segments)

Solution (Python):
data = input().split()
(n, t, c) = map(int, data[:3])
cr = list(map(int, input().split()))
count = 0
count2 = 0
for crime in cr:
    if crime <= t:
        count2 += 1
    else:
        if count2 >= c:
            count += count2 - c + 1
        count2 = 0
if count2 >= c:
    count += count2 - c + 1
print(count)