Shortest Job First Scheduling Algorithm Implementation Using C

Coding:

#include<stdio.h>

#include<conio.h>

#include<math.h>

struct ProcShedu

{

int pid;

int servicetime;

}process[100],temp;

main()

{

int Count=0,i=0,Wait=0,WaitTime=0,Turn=0,j=0;

clrscr();

printf("\n Enter No Of Proceses   ");

scanf("%d",&Count);

for(i=0;i<Count;i++)

{

printf("Enter No %d) Process ID   :",i+1);

scanf("%d",&process[i].pid);

printf("Enter Service Time        :");

scanf("%d",&process[i].servicetime);

}

for(i=0;i<Count;i++)

{

for(j=0;j<Count;j++)

{

if(process[i].servicetime<process[j].servicetime)

{

temp=process[i];

process[i]=process[j];

process[j]=temp;

}

}

}

printf("\n ID     Service     Wait    Total");

for(i=0;i<Count;i++)

{

WaitTime+=Wait;

printf("\n %d        %d        %d        %d",process[i].pid,process[i].servicetime,Wait,Wait+process[i].servicetime);

Wait=process[i].servicetime+Wait;

Turn+=Wait;

}

printf("\n Average Waiting Time   :%.2f",floor((float)WaitTime/(float)Count));

printf("\n Average Turnaround Time  :%.2f",floor((float)Turn/(float)Count));

getch();

}

Output:

 Enter No Of Proceses   3

Enter No 1) Process ID   :100

Enter Service Time        :24

Enter No 2) Process ID   :101

Enter Service Time        :3

Enter No 3) Process ID   :102

Enter Service Time        :3

 ID     Service     Wait    Total

 101        3        0        3

 102        3        3        6

 100        24        6        30

 Average Waiting Time   :3.00

 Average Turnaround Time  :13.00