Get busiest time - linear scan algorithm - look ahead technique, first 10 - 15 minutes using comparison to previous;

getBusiestTime_LinearIteration.cs

using System;

class Solution
{
  public static int FindBusiestPeriod(int[,] data)
  {
    // your code goes here
    if(data.GetLength(0) == 0 || data.GetLength(1) == 0)
    {
      return -1;
    }
    
    var rows = data.GetLength(0); 
   // var columns = data.GetLength(1); 
    
    var max = int.MinValue; 
    var maxTimeStamp = -1; 
    
    var sum = 0; 
    
    for(int row = 0; row < rows; row++)  // 25, 2
    {
      var currentTime = data[row, 0]; // 25, 25, 78
      var number = data[row, 1];   // 14, 4, 2, 10 
      var direction = data[row, 2]; // 1, 0, 0 , 1
      
      var isEntrance = direction == 1; // true, false, false , true
      var isLastRow =  row == rows - 1; // false, false , false , false
      //var startNewTime = currenttime != previousTimeStamp; // true
      
      sum = isEntrance? (sum + number) : (sum - number); // true? 14  //update new time, 14 - 4= 10, 10 - 2 = 8 , 8 + 10 = 18
      
      var readyToCompare = isLastRow || data[row + 1, 0] != currentTime;  // false , false , true, true 
      
      if(readyToCompare) // false 
      {        
        var currentIsBigger = sum > max; // 8
        if(currentIsBigger)          
        {
          max = sum; // 8 ....
          maxTimeStamp = currentTime; // 25                    
        }                 
      }
    }
    
    return maxTimeStamp; 
  }

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

// 25   14 1 -> 14 entrance, n   n + 14
// 25   4  0 -> 4 exit, n + 14 - 4
// 25   2  0 -> 2 exit, n + 14 - 4 - 2

// at 25 : + 8
// 78   78 != 25,  n + 14 - 4 -2 = n + 8 compared to max value int.MinValue, 

//+18 at 378