Find interval - 30 minutes practice -

FirstAvailableInterval_30minutePractice.cs

using System;

class Solution
{
    public static int[] MeetingPlanner(int[,] slotsA, int[,] slotsB, int dur) // dur =8
    {
      if(dur <= 0 || slotsA.GetLength(0) == 0 || slotsA.GetLength(1) != 2 ||
        slotsB.GetLength(0) == 0 || slotsB.GetLength(1) != 2) // false
      {
        return new int[] {}; 
      }
      
      var lengthA = slotsA.GetLength(0); // 3
      var lengthB = slotsB.GetLength(0); // 2
      
      int indexA = 0; 
      int indexB = 0; 
      
      while(indexA < lengthA && indexB < lengthB) // 
      {
        var visitStartA = slotsA[indexA, 0]; //10
        var visitStartB = slotsB[indexB, 0]; // 0 
        
        var visitEndA = slotsA[indexA, 1]; // 50
        var visitEndB = slotsB[indexB, 1]; // 15
        
        var maxStart = Math.Max(visitStartA, visitStartB); // 50
        var minEnd = Math.Min(visitEndA, visitEndB); // 15
        
        var hasOverlap = maxStart < minEnd; // 10 < 15 - true
        if(hasOverlap)
        {
          var intervalLength = minEnd - maxStart; // 5
          if(intervalLength >= dur ) // false 
          {
            return new int[] {maxStart, maxStart + dur}; 
          }
          else 
          {
            // move one slot further 
            if(visitEndA < visitEndB) // 
            {
              indexA++; 
            }
            else 
            {
              indexB++; // 1
            }
          }
        }               
      }
      
      return new int[0]; 
    }

    static void Main(string[] args)
    {
        
    }
}

/*
0   10     50    60       120   140       210
-----------------------------------------------------------------------------------
    <------>     <--------->    <---------->
<------>         <--->
___________________________________________________________________________________
       15            70
       [60, 68]
       
 overlap -> [max(start1, start2), min(end1, end2)], interval 
 ----
       ______  no overlap 
       first check if there is overlap
       there is interval 
       _______          _____
       ________________________
       
       move the interval with smaller end time 
       
       time complexity - O(m + n)  
       space complexity  - O(1)
       
*/