Define a structure for a student having name, roll number, and marks obtained in six subjects. Assume that “allstudents” is an array of students. Write a C program to print the name and roll numbers of the students who have secured highest marks in each subject.

#include<stdio.h>
struct student
{
    char name[100];
    int rollno,sub1,sub2,sub3,sub4,sub5,sub6;
};

main()
{
    struct student allstudent[100];
    int n,i,max;
    printf("\nEnter number of students=");
    scanf("%d",&n);
    for(i=0;i<n;i++)
    {
        printf("\nEnter name of student %d=",i+1);
        scanf("%s",allstudent[i].name);
        printf("\nEnter roll number of student %d=",i+1);
        scanf("%d",&allstudent[i].rollno);
        printf("\nEnter marks of student %d=",i+1);
        printf("\nSubject 1=");
        scanf("%d",&allstudent[i].sub1);
        printf("\nSubject 2=");
        scanf("%d",&allstudent[i].sub2);
        printf("\nSubject 3=");
        scanf("%d",&allstudent[i].sub3);
        printf("\nSubject 4=");
        scanf("%d",&allstudent[i].sub4);
        printf("\nSubject 5=");
        scanf("%d",&allstudent[i].sub5);
        printf("\nSubject 6=");
        scanf("%d",&allstudent[i].sub6);
    }
    printf("\nName\tRoll Number\tSubject 1\tSubject 2\tSubject 3\tSubject 4\tSubject 5\tSubject 6");
    for(i=0;i<n;i++)
    {
        printf("\n%s",allstudent[i].name);
        printf("\t\t%d",allstudent[i].rollno);
        printf("\t\t%d",allstudent[i].sub1);
        printf("\t\t%d",allstudent[i].sub2);
        printf("\t\t%d",allstudent[i].sub3);
        printf("\t\t%d",allstudent[i].sub4);
        printf("\t\t%d",allstudent[i].sub5);
        printf("\t\t%d\n",allstudent[i].sub6);       
    }

    max=0;
    for(i=1;i<n;i++)
    {
        if(allstudent[max].sub1<allstudent[i].sub1)
        {
            max=i;
        }
    }
    printf("\nThe maximum mark in subject1");
    printf("\nName=%s,Roll Number=%d,Mark=%d",allstudent[max].name,allstudent[max].rollno,allstudent[max].sub1);
   
    max=0;
    for(i=1;i<n;i++)
    {
        if(allstudent[max].sub2<allstudent[i].sub2)
        {
            max=i;
        }
    }
    printf("\nThe maximum mark in subject2");
    printf("\nName=%s,Roll Number=%d,Mark=%d",allstudent[max].name,allstudent[max].rollno,allstudent[max].sub2);
   
    max=0;
    for(i=1;i<n;i++)
    {
        if(allstudent[max].sub3<allstudent[i].sub3)
        {
            max=i;
        }
    }
    printf("\nThe maximum mark in subject3");
    printf("\nName=%s,Roll Number=%d,Mark=%d",allstudent[max].name,allstudent[max].rollno,allstudent[max].sub3);
   
    max=0;
    for(i=1;i<n;i++)
    {
        if(allstudent[max].sub4<allstudent[i].sub4)
        {
            max=i;
        }
    }
    printf("\nThe maximum mark in subject4");
    printf("\nName=%s,Roll Number=%d,Mark=%d",allstudent[max].name,allstudent[max].rollno,allstudent[max].sub4);
   
    max=0;
    for(i=1;i<n;i++)
    {
        if(allstudent[max].sub5<allstudent[i].sub5)
        {
            max=i;
        }
    }
    printf("\nThe maximum mark in subject5");
    printf("\nName=%s,Roll Number=%d,Mark=%d",allstudent[max].name,allstudent[max].rollno,allstudent[max].sub5);
    max=0;
    for(i=1;i<n;i++)
    {
        if(allstudent[max].sub6<allstudent[i].sub6)
        {
            max=i;
        }
    }
    printf("\nThe maximum mark in subject6");
    printf("\nName=%s,Roll Number=%d,Mark=%d",allstudent[max].name,allstudent[max].rollno,allstudent[max].sub6);
}