Day-7 Leetcode Coding Journey: Mastering Problem-Solving Techniques

Leetcode #56 Merge Intervals

Problem Statement:

Given a collection of intervals, merge all overlapping intervals and return an array of the non-overlapping intervals that cover all the intervals in the input.

Constraints

1 ≤ intervals.length ≤ 10^4
intervals[i].length == 2
-10^4 ≤ intervals[i][0] ≤ intervals[i][1] ≤ 10^4

🚀 Code Implementation

class Solution(object):
    def merge(self, intervals):
        """
        :type intervals: List[List[int]]
        :rtype: List[List[int]]
        """
        intervals.sort(key=lambda x: x[0])
        merged=[]
        for interval in intervals:
            if not merged or merged[-1][1]<interval[0]:
                merged.append(interval)
            else:
                merged[-1][1]=max(merged[-1][1],interval[1])
        return merged

Leetcode #57 Insert Interval

Problem Statement:

Given a set of non-overlapping intervals and a new interval, insert the new interval into the intervals such that the resulting intervals remain non-overlapping and sorted by the start time.

Constraints

1 ≤ intervals.length ≤ 10^4
intervals[i].length == 2
-10^4 ≤ intervals[i][0] ≤ intervals[i][1] ≤ 10^4
The input list of intervals is already sorted by the start time.

🚀 Code Implementation

class Solution(object):
    def insert(self, intervals, newInterval):
        """
        :type intervals: List[List[int]]
        :type newInterval: List[int]
        :rtype: List[List[int]]
        """
        result=[]
        i=0
        while i<len(intervals) and intervals[i][1] < newInterval[0]:
            result.append(intervals[i])
            i=i+1
        while i<len(intervals) and intervals[i][0]<=newInterval[1]:
            newInterval[0] = min(newInterval[0],intervals[i][0])
            newInterval[1] = max(newInterval[1],intervals[i][1])
            i=i+1
        result.append(newInterval)
        while i<len(intervals):
            result.append(intervals[i])
            i=i+1
        return result