Apply recommended fixes from PR review

Author: mdhvg

cpu_scheduling_algorithms/fcfs.py

@@ -13,40 +13,46 @@ def fcfs(processes: list[tuple[int, int, int]]) -> None:
 
     processes: list of tuples where each tuple contains the
     process_id, arrival_time and burst_time of each process
+
+    >>> processes = [(1, 0, 3), (2, 2, 7), (3, 1, 4), (4, 5, 2)]
+    >>> fcfs(processes)
+    Average Waiting Time: 6.0
+    *---*----*-------*--
+    1   3    2       4
     """
-    n = len(processes)
-    processes.sort(key=lambda x: x[1])
-    waiting_times = [0] * n
+    total_processes = len(processes)
+    processes.sort(key=lambda process: process[1])
+    waiting_times = [0] * total_processes
     total_waiting_time = 0
 
-    for i in range(1, n):
+    for i in range(1, total_processes):
         waiting_times[i] = processes[i - 1][2] + waiting_times[i - 1]
         total_waiting_time += waiting_times[i]
 
-    print(f"Average Waiting Time: {total_waiting_time / n}")
+    print(f"Average Waiting Time: {total_waiting_time / total_processes}")
 
     """
     Printing the Gantt Chart for the processes in the FCFS order
     The - and * symbols are used to represent the burst time and
     idle time respectively for each process.
     """
     last_burst = 0
-    for i in range(n):
+    for i in range(total_processes):
         print("-" * last_burst, end="")
         print("*", end="")
         last_burst = processes[i][2]
     print("-" * last_burst, end="")
     print("\n", end="")
 
     last_burst = 0
-    for i in range(n):
+    for i in range(total_processes):
         print(" " * last_burst, end="")
         print(f"{processes[i][0]}", end="")
         last_burst = processes[i][2]
     print("\n", end="")
 
 
-def main():
+def main() -> None:
     """
     Main function to demonstrate the FCFS CPU scheduling algorithm
     pass an array of (process_id, arrival_time, burst_time) to fcfs