Student Result Program in C Languiage

//Report sorted on total->Highest total to lowest
void main()
{
int i,j,k,m,n,roll[5];

float mark[5][4],total[5]={0},temp;
clrscr();
printf("Marks entry for how many students (max. 5) ? ");
scanf("%d",&m);
printf("Marks entry for how many papers (max. 4) ? ");
scanf("%d",&n);
for(i=0;i<m;i++)
{
printf("Enter Roll number :- ");
scanf("%d",&roll[i]);
printf("Enter marks for his/her papers \n");
for(j=0;j<n;j++)
{
printf("paper (%d) : ",j+1);
scanf("%f",&mark[i][j]);
total[i]+=mark[i][j];
}
}

//Sort Student list based on total marks obtained
for(i=0;i<m-1;i++)
{
for(j=i+1;j<m;j++)
{
if(total[i]<total[j])
{
temp=total[i];
total[i]=total[j];
total[j]=temp;

temp=roll[i];
roll[i]=roll[j];
roll[j]=temp;

//Sort rows
for(k=0;k<n;k++)
{
temp=mark[i][k];
mark[i][k]=mark[j][k];
mark[j][k]=temp;
}
}
}
  }
printf("Result    \n\n");
for(i=0;i<m;i++)
{
printf("\n%d \t",roll[i]);
for(j=0;j<n;j++)
{
printf("%3.2f\t",mark[i][j]);
}
printf("%3.2f\t",total[i]);
}

getch();
}