it seems to me that the recursive approach is not necessary...

> #include	<stdio.h>
> #include	<stdlib.h>
> 
> void max_sum_left(int *array_num, int n, int *array_sum)
> {
> 	int sum = 0;
> 	int max_sum = array_num[0];
> 	array_sum[0] = array_num[0];
> 
> 	int i;
> 	for (i = 1; i < n; ++i){
> 		sum += array_num[i];
> 		if (max_sum < sum) max_sum = sum;
> 		if (0 > sum) sum = 0;
> 		array_sum[i] = max_sum;
> 	}
> };
> 
> void max_sum_right(int *array_num, int n, int *array_sum)
> {
> 	int sum = 0;
> 	int max_sum = array_num[n - 1];
> 	array_sum[n - 1] = array_num[n - 1];
> 
> 	int i;
> 	for (i = n - 2; i > -1; --i){
> 		sum += array_num[i];
> 		if (max_sum < sum) max_sum = sum;
> 		if (0 > sum) sum = 0;
> 		array_sum[i] = max_sum;
> 	}
> };
> 
> int max_sum(int *array_num, int n)
> {
> 	int *array_left = (int *)malloc(sizeof(int) * n);
> 	int *array_right = (int *)malloc(sizeof(int) * n);
> 
> 	max_sum_left(array_num, n, array_left);
> 	max_sum_right(array_num, n, array_right);
> 
> 	int sum = array_left[0] + array_right[1];
> 	int max_sum = sum;
> 
> 	int i;
> 	for (i = 1; i < n - 1; ++i){
> 		sum = array_left[i] + array_right[i + 1];
> 		max_sum = (sum > max_sum) ? sum : max_sum;
> 	}
> 
> 	free(array_left);
> 	free(array_right);
> 	return max_sum;
> };
> 
> void loop()
> {
> 	int n;
> 	scanf("%d", &n);
> 
> 	int * array_num;
>         array_num = (int *) malloc(sizeof(int) * n);
> 
> 	int i = 0;
> 	int in;
> 	while (i < n){
> 		scanf("%d", &in);
> 		array_num[i] = in;
> 		++i;
> 	}
> 
> 	printf("%d\n", max_sum(array_num, n));
> 	free(array_num);
> };
> 
> int main(void)
> {
> 	int n;
> 	scanf("%d", &n);
> 
> 	int i = 0;
> 	while (i++ < n){
> 		getchar();
> 		loop();
> 	}
> 	return 0;
> };