4 What does the following program do by observation To be mo

4. What does the following program do (by observation)? To be more precise, what is the underlying meaning of the program? #include int mystery(int a, int b); // function prototype int main(void) { int x; //first integer int y; //second integer printf(\"Enter two integers: \"); scanf(\"%d%d\", &x, &y); printf(\"The result is %d\ \", mystery(x, y)); return 0; } /*Parameter b must be a positive integer to prevent infinite recursion*/ int mystery( int a, int b) { if (b == 1) return a; else return a + mystery (a, b-1); }

Solution

#include <stdio.h>
int mystery(int a, int b); // function prototype
int main(void)
{
int x; //first integer
int y; //second integer
printf(\"Enter two integers: \");    //Prompts to enter 2 integers.
scanf(\"%d%d\", &x, &y);            //Reads the values into the variables x, and y.
printf(\"The result is %d\ \", mystery(x, y));    //Prints the returned value from the function mystery(x, y).
return 0;
}
/*Parameter b must be a positive integer to prevent infinite recursion*/
int mystery( int a, int b)
{
if (b == 1)   //If the second variable entered is 1.
return a;    //Return the first value.
else           //If not.
return a + mystery (a, b-1);   //Return the value returned by mystery(a, b-1) added to a.
}

//The mystery method will keep adding the values of a repeatedly for b times, and the result will be printed.
//Which means, the multiplication of a * b will be returned and printed to the screen.