Read the C code given below. What would be the output of the
following program? Justify your answer.
#include <stdio.h>
int myrecurse(int a, int b){
return (b == 1 ? a: myrecurse(a, b-1) + a);
}
main() {
int a[]= {2,3,4,5,6};
int i, x;
for (i = sizeof(a)/sizeof(*a), x = 0; --i; )
x += myrecurse(*(a+i), a[i-1]);
printf("\nThe result is: %d", x);
}
(b) Suppose you are given a sequence $S = < x_1, x_2, . . . , x_n >$ of $n$ integers. For $1 ≤ i ≤ j ≤ n$, the sequence $< x_i, x_{i+1},.. . . , x_j >$ of consecutive elements is called a subsequence of S. The sum of a subsequence is the sum of the integers in that subsequence. Give an $O(n log n)$ algorithm to determine whether the given sequence $S$ has a subsequence whose sum is zero, and justify the correctness of the algorithm.