# Program to count number of intervals which are intersecting at given point in Python

Suppose we have a list of intervals and a value called point. Each interval interval[i] contains [si, ei] represents start time and end time of interval i (both inclusive). We have to find the number of intervals that are intersecting at given point.

So, if the input is like intervals = [[2, 6],[4, 10],[5, 9],[11, 14]] point = 5, then the output will be 3, because at time 5, there are 3 intervals those are [3, 6], [4, 10], [5, 9]

To solve this, we will follow these steps −

• count := 0

• for each start time i and end time j in intervals, do

• if point >= i and point <= j, then

• count := count + 1

• return count

## Example

Let us see the following implementation to get better understanding

def solve(intervals, point):
count = 0
for i, j in intervals:
if point >= i and point <= j:
count += 1
return count

intervals = [[2, 6],[4, 10],[5, 9],[11, 14]]
point = 5
print(solve(intervals, point))

## Input

[[2, 6],[4, 10],[5, 9],[11, 14]], 5


## Output

3

Updated on: 11-Oct-2021

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