C++ Program to count number of student with distinction,first division,second division,third division and failed

/*To read marks of 4 subjects and find out how many students fall under the following categories:

a) avg<45 - Fail
b) 45 <= avg <55- Third Division
c) 55<= avg <60 - Second Division
d) 60<= avg <75 - First Division
e) avg >=75 - Distinction
*/
#include<stdio.h>
#include<conio.h>
main()
{
      int f=0,t=0,s=0,F=0,d=0,n,i;
      float fcp,iit,cag,stat;
      printf("Enter the number of students\n");
      scanf("%d",&n);
      float avg[n];
      for(i=0;i<n;i++)
      {
                      printf("Enter marks of FCP , IIT , CAG , STAT respectively of %dth student\n",i+1);
                      scanf("%f%f%f%f",&fcp,&iit,&cag,&stat);
                      avg[i]=(fcp+iit+cag+stat)/4;
                      printf("Avrage=%f\n",avg[i]);
                      }
                   
       for(i=0;i<n;i++)
      {
                       if(avg[i]<45)
                       f++;
                       if(avg[i]<75 && avg[i]>=60)
                       F++;
                       if(avg[i]<55 && avg[i]>=45)
                       t++;
                       if(avg[i]<60 && avg[i]>=55)
                       s++;
                       if(avg[i]>=75)
                       d++;
                       }
                       printf("The number of students with distinction = %d\n",d);
                       printf("The number of students with first division = %d\n",F);
                       printf("The number of students with second division = %d\n",s);
                       printf("The number of students with third division = %d\n",t);
                       printf("The number of failed students = %d\n",f);
                       getch();
                       }