// C++ program for implementation of FCFS
// scheduling
#include<bits/stdc++.h>
using namespace std;
 
struct Process
{
    int pid;  // Process ID
    int bt;   // CPU Burst time required
    int priority; // Priority of this process
};
 
// Function to sort the Process acc. to priority
bool comparison(Process a, Process b)
{
    return (a.priority > b.priority);
}
 
// Function to find the waiting time for all
// processes
void findWaitingTime(Process proc[], int n,
                     int wt[])
{
    // waiting time for first process is 0
    wt[0] = 0;
 
    // calculating waiting time
    for (int  i = 1; i < n ; i++ )
        wt[i] =  proc[i-1].bt + wt[i-1] ;
}
 
// Function to calculate turn around time
void findTurnAroundTime( Process proc[], int n,
                         int wt[], int tat[])
{
    // calculating turnaround time by adding
    // bt[i] + wt[i]
    for (int  i = 0; i < n ; i++)
        tat[i] = proc[i].bt + wt[i];
}
 
//Function to calculate average time
void findavgTime(Process proc[], int n)
{
    int wt[n], tat[n], total_wt = 0, total_tat = 0;
 
    //Function to find waiting time of all processes
    findWaitingTime(proc, n, wt);
 
    //Function to find turn around time for all processes
    findTurnAroundTime(proc, n, wt, tat);
 
    //Display processes along with all details
    cout << "\nProcesses  "<< " Burst time  "
         << " Waiting time  " << " Turn around time\n";
 
    // Calculate total waiting time and total turn
    // around time
    for (int  i=0; i<n; i++)
    {
        total_wt = total_wt + wt[i];
        total_tat = total_tat + tat[i];
        cout << "   " << proc[i].pid << "\t\t"
             << proc[i].bt << "\t    " << wt[i]
             << "\t\t  " << tat[i] <<endl;
    }
 
    cout << "\nAverage waiting time = "
         << (float)total_wt / (float)n;
    cout << "\nAverage turn around time = "
         << (float)total_tat / (float)n;
}
 
void priorityScheduling(Process proc[], int n)
{
    // Sort processes by priority
    sort(proc, proc + n, comparison);
 
    cout<< "Order in which processes gets executed \n";
    for (int  i = 0 ; i <  n; i++)
        cout << proc[i].pid <<" " ;
 
    findavgTime(proc, n);
}
 
// Driver code
int main()
{
    Process proc[] = {{1, 10, 2}, {2, 5, 0}, {3, 8, 1}};
    int n = sizeof proc / sizeof proc[0];
    priorityScheduling(proc, n);
    return 0;
}