RECURSION

RECURSION
Introduction
You can express most of the problems in the following program by using recursion. We represent the function add by using recursion.
Program#include
int add(int pk,int pm);
main()
{
int k ,i,m;
m=2;
k=3;
i=add(k,m);.
printf("The value of addition is %d\n",i);
}
int add(int pk,int pm)
{
if(pm==0) return(pk); \\ A
else return(1+add(pk,pm-1)); \\ B
}
Explanation
The add function is recursive as follows:add (x, y) = 1 + add(x, y-1) y > 0
= x y = 0
for example,
add(3, 2) = 1 + add(3, 4)
add(3, 1) = 1 + add(3, 0)
add(3, 0) = 3
add(3, 1) = 1+3 = 4
add(3, 2) = 1+4 = 5
The recursive expression is 1+add(pk, pm-1). The terminating condition is pm = 0 and the recursive condition is pm > 0.