Merge pull request darpanjbora#116 from shanvijha30/FCFSalgo

darpanjbora · web-flow · commit 154023749f7a · 2022-10-11T12:45:42.000+05:30
First Come First Serve Algorithm
diff --git a/Operating Systems/FCFS.java b/Operating Systems/FCFS.java
@@ -0,0 +1,77 @@
+// Java program for implementation of FCFS
+// scheduling
+
+import java.text.ParseException;
+
+class FCFS {
+
+	// Function to find the waiting time for all
+	// processes
+	static void findWaitingTime(int processes[], int n,
+			int bt[], int wt[]) {
+		// waiting time for first process is 0
+		wt[0] = 0;
+
+		// calculating waiting time
+		for (int i = 1; i < n; i++) {
+			wt[i] = bt[i - 1] + wt[i - 1];
+		}
+	}
+
+	// Function to calculate turn around time
+	static void findTurnAroundTime(int processes[], int n,
+			int bt[], int wt[], int tat[]) {
+		// calculating turnaround time by adding
+		// bt[i] + wt[i]
+		for (int i = 0; i < n; i++) {
+			tat[i] = bt[i] + wt[i];
+		}
+	}
+
+	//Function to calculate average time
+	static void findavgTime(int processes[], int n, int bt[]) {
+		int wt[] = new int[n], tat[] = new int[n];
+		int total_wt = 0, total_tat = 0;
+
+		//Function to find waiting time of all processes
+		findWaitingTime(processes, n, bt, wt);
+
+		//Function to find turn around time for all processes
+		findTurnAroundTime(processes, n, bt, wt, tat);
+
+		//Display processes along with all details
+		System.out.printf("Processes 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];
+			System.out.printf(" %d ", (i + 1));
+			System.out.printf("	 %d ", bt[i]);
+			System.out.printf("	 %d", wt[i]);
+			System.out.printf("	 %d\n", tat[i]);
+		}
+		float s = (float)total_wt /(float) n;
+		int t = total_tat / n;
+		System.out.printf("Average waiting time = %f", s);
+		System.out.printf("\n");
+		System.out.printf("Average turn around time = %d ", t);
+	}
+
+	// Driver code
+	public static void main(String[] args) throws ParseException {
+		//process id's
+		int processes[] = {1, 2, 3};
+		int n = processes.length;
+
+		//Burst time of all processes
+		int burst_time[] = {10, 5, 8};
+
+		findavgTime(processes, n, burst_time);
+
+	}
+}
+
+
