scheduling

Scheduling/fcfs.c

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+// C program for implementation of FCFS 
+// scheduling 
+#include<stdio.h> 
+// Function to find the waiting time for all 
+// processes 
+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 
+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 
+void findavgTime( int processes[], int n, int bt[]) 
+{ 
+	int wt[n], tat[n], 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 
+	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]; 
+		printf(" %d ",(i+1)); 
+		printf("	 %d ", bt[i] ); 
+		printf("	 %d",wt[i] ); 
+		printf("	 %d\n",tat[i] ); 
+	} 
+	int s=(float)total_wt / (float)n; 
+	int t=(float)total_tat / (float)n; 
+	printf("Average waiting time = %d",s); 
+	printf("\n"); 
+	printf("Average turn around time = %d ",t); 
+} 
+
+// Driver code 
+int main() 
+{ 
+	//process id's 
+	int processes[] = { 1, 2, 3}; 
+	int n = sizeof processes / sizeof processes[0]; 
+
+	//Burst time of all processes 
+	int burst_time[] = {10, 5, 8}; 
+
+	findavgTime(processes, n, burst_time); 
+	return 0; 
+} 

Scheduling/sjf.c

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+#include<stdio.h>
+int main()
+{
+    int bt[20],p[20],wt[20],tat[20],i,j,n,total=0,pos,temp;
+    float avg_wt,avg_tat;
+    scanf("%d",&n);
+    for(i=0;i<n;i++)
+    {
+        scanf("%d",&bt[i]);
+        p[i]=i+1;  
+    }
+    for(i=0;i<n;i++)
+    {
+        pos=i;
+        for(j=i+1;j<n;j++)
+        {
+            if(bt[j]<bt[pos])
+                pos=j;
+        }
+        temp=bt[i];
+        bt[i]=bt[pos];
+        bt[pos]=temp;
+
+        temp=p[i];
+        p[i]=p[pos];
+        p[pos]=temp;
+    }
+    wt[0]=0;          
+    printf("wt: ");
+    for(i=0;i<n;i++)
+    {
+        wt[i]=0;
+        for(j=0;j<i;j++)
+        {
+          wt[i]+=bt[j];
+        }
+        printf("%d      ",wt[i]);
+      total+=wt[i];
+    }
+    avg_wt=(float)total/n;     
+    total=0;
+    printf("\nTAT: ");
+    for(i=0;i<n;i++)
+    {
+        tat[i]=bt[i]+wt[i];     //calculate turnaround time
+        total+=tat[i];
+        printf("%d      ",tat[i]);
+    }
+
+    avg_tat=(float)total/n; 
+    printf("Average Waiting Time:%0.6f",avg_wt);
+    printf("\nAverage Turnaround Time:%0.6f",avg_tat);  
+    return 0;
+}