# Program to find intervals by merging target interval in Python

PythonServer Side ProgrammingProgramming

Suppose we have a list of non-overlapping intervals. These are sorted based on end time. We have another interval target, find final interval after merging target so that intervals are still non-overlapping and sorted.

So, if the input is like intervals = [[1, 15],[25, 35],[75, 90]], target = [10, 30], then the output will be [[1, 35], [75, 90]] as first two intervals [1, 15] and [25, 35] are merged.

To solve this, we will follow these steps −

• insert target at the end of iv

• sort iv based on start time

• res := a new list with first interval

• i := 1

• while i < size of iv, do

• if start time of iv[i] <= end time of last interval of res, then

• end time of last interval of res = maximum of (end time of last interval of res and end time of iv[i])

• otherwise,

• insert iv[i] at the end of res

• i := i + 1

• return res

## Example (Python)

Let us see the following implementation to get a better understanding −

Live Demo

class Solution:
def solve(self, iv, target):
iv.append(target)
iv.sort(key=lambda x: x)
res = [iv]
i = 1
while i < len(iv):
if iv[i] <= res[-1]:
res[-1] = max(res[-1], iv[i])
else:
res.append(iv[i])
i += 1
return res
ob = Solution()
intervals = [
[1, 15],
[25, 35],
[75, 90]
]
target = [10, 30]
print(ob.solve(intervals, target))

## Input

[[1, 15],[25, 35],[75, 90]], [10, 30]

## Output

[[1, 35], [75, 90]]