Shortest Remaining Time First

C Program For Shortest Remaining Time First(SRTF)

Source Code:

#include <stdio.h>
#include <stdlib.h>

struct Process
{
 int id;
 int btime;
 int atime;
 int isdone;
 int wtime;
 int ttime;
};

int cmp(const void *a, const void *b)
{
 struct Process* a1 = (struct Process*)a;
 struct Process* b1 = (struct Process*)b;
 return (a1->atime - b1->atime);
}

int allComplete(struct Process *p, int n)
{
 int i;
 for (i = 0; i < n; i++) {
  if (p[i].isdone != 1) {
   return 0;
  }
 }
 return 1;
}

int main()
{
 struct Process* p;
 int i, n, g[50], j, currentTime = 0, min, k, total = 0, y = 0, m = 0;
 printf("Enter Number Of Process: ");
 scanf("%d", &n);

 p = (struct Process*)malloc(sizeof(struct Process) * n);
 
 for(i = 0; i < n; i++) {
     printf("Enter The Brust Time Of Process %d: ", i);
  scanf("%d", &p[i].btime);
  printf("Enter Arrival Time Of Process %d: ", i);
  scanf("%d", &p[i].atime);
  p[i].id = i;
  p[i].isdone = 0;
  total += p[i].btime;
  p[i].ttime = 0;
  p[i].wtime = 0;
 }

 qsort(p, n, sizeof(struct Process), cmp);

 printf("Process\tATime\tBTime\n");
 for (i = 0; i < n; ++i) {
  printf("P%d\t%d\t%d\n",p[i].id, p[i].atime, p[i].btime);
 }
 p[n].atime = 999;
 int lstTime = p[n-1].atime;

 
 while(!allComplete(p, n)) {
  for(y = 0; y < n; y++) { if(p[y].isdone != 1 && p[y].btime != 999) min = y; break;}
  for (k = 1; k < n; k++) {
   printf("%d < %d && %d < %d && %d == %d \n",p[k].btime,p[min].btime,p[k].atime,currentTime, p[k].isdone, 0);
   if (p[k].btime < p[min].btime  && p[k].atime <= currentTime && p[k].isdone == 0) {
    min = k;
   }
  }
  printf("min is: %d\n",min);
  
  for (j = p[min].atime; j < p[min+1].atime && p[min].btime != 999; j++) {
   g[m++] = min;
   //printf("-");
    printf("\t%d: %d < %d\n", p[min].atime, j, p[min+1].atime);
   (p[min].btime)--;;
   currentTime++;
   if (p[min].btime == 0) {p[min].isdone = 1; p[min].atime = 999; p[min].btime = 999;}
  }
 }


 for(i = 0; i < total; i++)
  printf("P%d ",g[i]);

 return 0;
}