Which line should be inserted in the blank to

complete the following dynamic programming implementation of the maximum

sub-array sum problem?

#include<stdio.h>

int

max_num(int a,int b)

{

if(a> b)

           return a;

return b;

}

int

maximum_subarray_sum(int *arr, int

len)

{

int sum[len], idx;

sum[0] = arr[0];

for(idx = 1; idx <

len; idx++)

           sum[idx] = _______________________;

int mx = sum[0];

for(idx = 0; idx <

len; idx++)

           if(sum[idx] > mx)

               mx =sum[idx];

           return

mx;

}

int

main()

{

int arr[] = {-2, -5, 6, -2, 3, -1, 0,-5, 6}, len = 9;

int ans =

maximum_subarray_sum(arr,

len);

printf("%d",ans);

return 0;