Priority

Author: moazmohamed20

Priority.cpp

@@ -0,0 +1,98 @@
+#include <iostream>
+
+using namespace std;
+
+struct Process
+{
+ int num, arrive, burst, priority;
+};
+
+void sort(Process array[], int size)
+{
+ for (int i = 0; i < size; i++)
+ for (int j = i + 1; j < size; j++)
+ if (array[i].arrive > array[j].arrive)
+ {
+ Process temp = array[i];
+ array[i] = array[j];
+ array[j] = temp;
+ }
+}
+
+int Priority(Process processes[], int size, bool primitive)
+{
+ int totalWaitTime = 0;
+
+ // Order Received Processes List By Arrive Time
+ // We Need To Order By Arrive Time Because Many Processes May Have The Same Priority So We Choose What Came First
+ sort(processes, size);
+
+ // Copy Received Processes List To New List
+ Process *list = new Process[size];
+ for (int i = 0; i < size; i++)
+ list[i] = processes[i];
+
+ // Time Started... Let's Go Throw Processes
+ int time = 0;
+ while (true)
+ {
+ // 1) Find Highest Priority Number
+ int minIndex = -1;
+ int minPriority = 1000;
+ for (int i = 0; i < size; i++)
+ {
+ if (time >= list[i].arrive // If Process Has Arrived
+ && list[i].burst > 0 // And Not Used Before
+ && list[i].priority < minPriority)
+ {
+ minIndex = i;
+ minPriority = list[i].priority;
+ }
+ }
+
+ // 2) If The Process Was Ready (Arrived)
+ if (minIndex != -1)
+ {
+ // Don't Leave The Process Until It Is Finished
+ do
+ {
+ cout << time << " ~ " << time + 1 << "\t\t" << list[minIndex].num << endl;
+ list[minIndex].burst--;
+ time++;
+ } while (!primitive && list[minIndex].burst > 0);
+ if (list[minIndex].burst == 0)
+ totalWaitTime += time - processes[minIndex].arrive - processes[minIndex].burst;
+ }
+ // 3) If No Process Is Ready
+ else
+ {
+ // Check If There Is Any UnFinished Process
+ bool allFinished = true;
+ for (int i = 0; i < size; i++)
+ if (list[i].burst > 0)
+ {
+ allFinished = false;
+ cout << time << " ~ " << time + 1 << endl;
+ time++;
+ break;
+ }
+
+ if (allFinished)
+ break;
+ }
+ }
+
+ return totalWaitTime;
+}
+
+int main(int argc, char const *argv[])
+{
+ Process processes[] = {{1, 0, 1, 3}, {2, 3, 8, 4}, {3, 4, 5, 2}, {4, 5, 2, 2}, {5, 8, 4, 1}};
+
+ int totalWaitTime = 0;
+ totalWaitTime = Priority(processes, 5, false);
+ cout << "Total Waiting Time = " << totalWaitTime;
+
+ getchar();
+ return 0;
+}

README.md

@@ -4,3 +4,4 @@
 
 - First Come, First Served ( `FCFS` )
 - Shortest Job First ( **Preemptive** / **Non-Preemptive** ) ( `SJF` )
+- Priority ( **Preemptive** / **Non-Preemptive** )