1. I'm wondering how to compile this 3 source code in 1 program using case statement coz im having difficult to make it in 1 combined program..
i hope somebody could help me thanks ...

example :

[1] Sound
[2] Fibonacci numbers
[3] Multiplication of Matrices

please select a number:


1st code: Sound
Code:
#include <dos.h>
#include <stdio.h>
#include <stdlib.h>

int menu(void);


main()
{
while(1)
{
/*get selection and execute the relevant statement*/
switch(menu())
{
case 1:
{
puts("sound the speaker 1\n");
sound(2000);
sleep(2);
nosound();
break;
}
case 2:
{
puts("sound that speaker 2\n");
sound(4000);
sleep(2);
nosound();
break;
}
case 3:
{
puts("You are quitting\n");
exit(0);
break;
}
default:
{
puts("Invalid menu choice\n");
break;
}
}
}
return 0;
}

/*menu function*/
int menu(void)
{
int reply;
/*display menu options*/
puts("Enter 1 for beep 1.\n");
puts("Enter 2 for beep 2.\n");
puts("Enter 3 to quit.\n");
/*scan for user entry*/
scanf("%d", &reply);

return reply;
}
2nd code: Fibonacci numbers
Code:
#include <stdio.h>

int main(void) {
    int n;        /* The number of fibonacci numbers we will print */
    int i;        /* The index of fibonacci number to be printed next */ 
    int current;  /* The value of the (i)th fibonacci number */
    int next;     /* The value of the (i+1)th fibonacci number */
    int twoaway;  /* The value of the (i+2)th fibonacci number */

    printf("How many Fibonacci numbers do you want to compute? ");
    scanf("%d", &n);
    if (n<=0)
       printf("The number should be positive.\n");
    else {
      printf("\n\n\tI \t Fibonacci(I) \n\t=====================\n");
      next = current = 1;
      for (i=1; i<=n; i++) {
 printf("\t%d \t   %d\n", i, current);
 twoaway = current+next;
 current = next;
 next    = twoaway;
      }
    }
return 0;
}

/* The output from a run of this program was:

How many Fibonacci numbers do you want to compute? 9

 I   Fibonacci(I) 
 =====================
 1     1
 2     1
 3     2
 4     3
 5     5
 6     8
 7     13
 8     21
 9     34

*/
3rd Code: Multiplication of Matrices
Code:
#include<stdio.h> 
#include<conio.h> 
void main() 
{ 
int mat1[2][2],mat2[2][2],mat3[2][2],i,j,k;
clrscr();
printf("************A program to find the multiplication of the given matrices***********\n\n"); 
printf("************Enter the value for the 1st matrix************\n"); 
for(i=0;i<2;i++) 
{ 
for(j=0;j<2;j++) 
{ 
printf("\nEnter the value for %d row,%d column:",i+1,j+1); 
scanf("%d",&mat1[i][j]); 
} 
} 
printf("\n************Enter the value for the 2nd matrix************\n"); 
for(i=0;i<2;i++) 
{ 
for(j=0;j<2;j++) 
{ 
printf("\nEnter the value for %d row,%d column:",i+1,j+1); 
scanf("%d",&mat2[i][j]); 
} 
} 
printf("\n****************************The given matrices are*****************************\n\n"); 
for(i=0;i<2;i++) 
{ 
for(j=0;j<2;j++) 
{ 
printf("%d\t",mat1[i][j]); 
} 
printf("\n"); 
} 
printf("\n\n"); 
for(i=0;i<2;i++) 
{ 
for(j=0;j<2;j++) 
{ 
printf("%d\t",mat2[i][j]); 
} 
printf("\n"); 
} 
printf("\n****************************The multiplication of the matrices is*************\n\n"); 
for(i=0;i<2;i++) 
{ 
for(j=0;j<2;j++) 
{ 
mat3[i][j]=0; 
for(k=0;k<2;k++) 
{ 
mat3[i][j]=mat3[i][j]+(mat1[i][k]*mat2[k][j]); 
} 
} 
} 
for(i=0;i<2;i++) 
{ 
for(j=0;j<2;j++) 
{ 
printf("%d\t",mat3[i][j]); 
} 
printf("\n"); 
} 

getch(); 
getch(); 
}