Minimum Platforms Java

PROGRAM TO FIND MINIMUM NUMBER OF PLATFORMS REQUIRED FOR A RAILWAY/BUS STATION




import java.util.*;

 

class GFG {

 

    // Returns minimum number of platforms reqquired

    static int findPlatform(int arr[], int dep[], int n)

    {

        // Sort arrival and departure arrays

        Arrays.sort(arr);

        Arrays.sort(dep);

 

        // plat_needed indicates number of platforms

        // needed at a time

        int plat_needed = 1, result = 1;

        int i = 1, j = 0;

 

        // Similar to merge in merge sort to process

        // all events in sorted order

        while (i < n && j < n) {

            // If next event in sorted order is arrival,

            // increment count of platforms needed

            if (arr[i] <= dep[j]) {

                plat_needed++;

                i++;

            }

 

            // Else decrement count of platforms needed

            else if (arr[i] > dep[j]) {

                plat_needed--;

                j++;

            }

 

            // Update result if needed

            if (plat_needed > result)

                result = plat_needed;

        }

 

        return result;

    }

 

    // Driver code

    public static void main(String[] args)

    {

        int arr[] = { 900, 940, 950, 1100, 1500, 1800 };

        int dep[] = { 910, 1200, 1120, 1130, 1900, 2000 };

        int n = arr.length;

        System.out.println("Minimum Number of Platforms Required = "

                           + findPlatform(arr, dep, n));

    }

}







OUTPUT:

Minimum Number of Platforms Required = 3

CREDITS: https://www.geeksforgeeks.org/minimum-number-platforms-required-railwaybus-station/