One Interval.py

"""
Intuition
First of all we merge the intervals which overlap with each other. Then return the difference of (start of the last element) and (end of the first element).
"""
class Solution:
    def solve(self, intervals):
        if len(intervals) == 1:
            return 0
        intervals.sort()
        ls = [intervals[0]]
        for i in range(1, len(intervals)):
            if ls[-1][1] >= intervals[i][0]:
                ls[-1][1] = max(ls[-1][1], intervals[i][1])
            else:
                ls.append(intervals[i])
        if len(ls) == 1:
            return 0
        return ls[-1][0] - ls[0][1]