#include <stdio.h>

char subject[5][20]={
                  "science",
                  "Maths",
                  "CS",
                  "Social Studies",
                  "English"
                 };
void main()
{
    char student[30][30],ans;
    int marks[30][5],i,j,nos,stnum,sbnum;int junk;
    float studavg[30],subavg[5],var;
    float classavg[5];
    int ch;
    clrscr();
    /*Loop to accept names*/
    for (ans='y',i=0;i<30&&(ans=='y' || ans=='Y');i++ )
    {
    printf("\nEnter the name %d:",i+1);
    scanf("%s",student[i]);
    printf("\nDo you want to enter another name?(y/n):");
    scanf("%d",&junk);
    scanf("%c",&ans);
    }
    nos=i;
    for(i=0;i<nos;i++)
    {
	   for(j=0;j<5;j++)
	   {
		  printf("Enter the marks of %s in %s: ",student[i],subject[j]);
		  scanf("%d",&marks[i][j]);
	   }
	   printf("\n");
    }
	printf("\n\npress any key to continue");
	getch();
	while(ch!=5)
	{
	clrscr();
	printf("\nEnter a choice\n1. Display student name & marks\n2. Display each subject along with class average");
	printf("\n3. Display students names & subjects So that I can select details of particular student.\n4. Display Students who have scored more than 80.");
	printf("\n5. EXIT\n\nEnter the choice:");
	scanf("%d",&ch);
	switch(ch)
	{

		case 1:/*To calculate the average*/
				clrscr();
				for (i=0;i<nos;i++)
				{
					  for (var=0,j=0;j<5;j++)
					  {
						var=var+marks[i][j];
					  }
				  studavg[i]=(float)var/5;
				  printf("\nThe average for %s is %f",student[i],studavg[i]);
				}
				printf("\n\npress any key to continue");
				getch();
				break;

		case 2:/*To calculate class average*/
				clrscr();
				for (j=0;j<5;j++)
				{
				   for (var=0,i=0;i<nos;i++)
				  {
					  var=var+marks[i][j];
				  }
				classavg[j]=(float)var/nos;
				printf("\nClass average in %s is %5.2f",subject[j],classavg[j]);
			    }
			    printf("\n\npress any key to continue");
			    getch();
				break;

		case 3:/*Display students names & subjects & make selection among them*/
				clrscr();

				for(i=0;i<nos;i++)
				{
					if(i%5==0)
						printf("\n");
						printf("\t");
					printf("\n%2d. %s",i+1,student[i]);
				}
				printf("\nSelect a student from the list shown below(enter corresponding no)\n");
				scanf("%d",&stnum);
				stnum--;

				for(j=0;j<5;j++)
					printf("\n%2d. %s",j+1,subject[j]);
				printf("\nSelect the Subject(enter corresponding number)");
				scanf("%d",&sbnum);
				sbnum--;
				printf("\n%s has scored %d in %s",student[stnum],marks[stnum][sbnum],subject[sbnum]);
				printf("\n\npress any key to continue");
				getch();
				break;
		case 4:/*Display Students who have scored more than 80.*/
				clrscr();
				printf("\nFollowing is the list of students whose average is above 80%\n");
				for(i=0;i<nos;i++)
				{
					if(studavg[i]>=80)
						{
						if(i%3==0)
							printf("\n");
						else
							printf("\t\t");
						printf("%d. %s",i+1,student[i]);
						}
				}
				printf("\n\npress any key to continue");
				getch();
				break;
		case 5:break;
		default:clrscr();printf("\n\n\t\tCaution Invalid Choice!!!\n\n");

	}//switch
	}//while
	printf("\npress any key to EXIT");
	getch();
}//main