What does the following recursive function return when called as count_bits(13)?
int count_bits(int n) {
if (n == 0) return 0;
return (n & 1) + count_bits(n >> 1);
}13 in binary is 1101, which has three 1-bits.
What is printed by the call show(123) for the following function?
void show(int n) {
if (n == 0) return;
show(n / 10);
printf("%d", n % 10);
}Because the print is after the recursive call, digits are printed in original order: 123.
What is the return value of gcd(48, 18) using Euclid's recursive algorithm?
int gcd(int a, int b) {
if (b == 0) return a;
return gcd(b, a % b);
}gcd(48, 18) -> gcd(18, 12) -> gcd(12, 6) -> gcd(6, 0) returns 6.
What happens if a recursive function does not have a base case?
Without a base case, recursive calls continue indefinitely until stack memory is exhausted.
What is the output of the following C code?
#include <stdio.h>
int fun(int n) {
if (n == 1) return 0;
return 1 + fun(n / 2);
}
int main(void) {
printf("%d", fun(16));
return 0;
}fun(16) = 1 + fun(8) = 2 + fun(4) = 3 + fun(2) = 4 + fun(1) = 4 + 0 = 4 (calculates log2(16)).