Define a very basic PCB structure:
struct PCB {int ProcId; int ProcPR, int CPUburst; int Reg[8]; int queueEnterClock, waitingTime; /* other info */ struct PCB *next;}

Define a very basic CPU consisting of 8 integer registers: int CPUreg[8] = {0};
Initialize your linked list: struct PCB *Head=NULL; struct PCB *Tail=NULL;
Initialize your other data: int CLOCK=0; int Total_waiting_time=0; int Total_turnaround_time=0; int Total_job=0;
Open the input file
For each input line, read a line consisting of three integers: Process Id, Process Priority, CPU Burst time.
dynamically create a struct PCB pointed by PCB,
save the given data into corresponding fields of PCB,
set all PCB->Reg[8] to the Process ID, set PCB->queueEnterClock and PCB->waitingTime to 0, then
insert this PCB at the end of the link list.
Close input file
Print your name, the name of the scheduling algorithm, and the input file name, as mentioned before.
The above steps will be the same for the next session too
Now implement a FIFO_Scheduling() function and call it to print the order of completed processes.

This function simply removes the PCB from the head of the linked list and performs the followings until the linked list is empty:
Do context-switching:

copy PCB->Reg[8] into CPUreg[8],
suppose some work is done on CPU (e. g, increment each CPUreg by one),
copy CPUreg[8] into PCB->Reg[8]
Data collection for performance metrics
PCB->waitingTime = PCB->waitingTime + CLOCK - PCB->queueEnterClock;
Total_waiting_time = Total_waiting_time + PCB->waitingTime ;
CLOCK = CLOCK + PCB->CPUburst;
Total_turnaround_time = Total_turnaround_time + CLOCK;
Total_job = Total_job + 1;
Free PCB. Since there is no more CPUburst or I/O burst, this process is terminated here! Otherwise, it will be put in a ready or waiting queue.
Finally, print the perfromance metrics mentioned before:
Total_waiting_time / Total_job,
Total_turnaround_time / Total_job,
Total_job / CLOCK

For each input file, copy/paste your screen output into a text file (say output1.txt)
input1.txt:

1 3 5
2 3 7
3 1 6
4 5 4