src.c

#include <stdio.h>
#include <stdlib.h>
static inline int max(int a, int b)
{
	return a >= b ? a : b;
}
static inline int min(int a, int b)
{
	return a <= b ? a : b;
}
int get(int i)
{
	return i & 0x1;
}
int robWithoutCircle(int num[], int n) {
	int df[2];
	int i, result = -1;
	if (n <= 0)
		return 0;
	if (n == 1)
		return num[0];
	df[0] = num[0];
	df[1] = max(df[0], num[1]);
	result = max(df[0], df[1]);
	for (i = 2; i < n; ++i) {
		df[get(i)] = max(df[get(i - 2)] + num[i], df[get(i - 1)]);
		result = max(result, df[get(i)]);
	}
	return result;
}
int rob(int *nums, int n)
{
	if (nums == NULL || n <= 0)
		return 0;
	if (n == 1)
		return nums[0];
	return max(robWithoutCircle(nums, n - 1), robWithoutCircle(nums + 1, n - 1));
}
void print(int *a, int n)
{
	for (int i = 0; i < n; ++i)
		printf("%d ", a[i]);
	printf("\n");
}
int main(int argc, char **argv)
{
	int a[20], n;
	while (scanf("%d", &n) != EOF) {
		for (int i = 0; i < n; ++i)
			scanf("%d", &a[i]);
		print(a, n);
		printf("result = %d\n", rob(a, n));
	}
	return 0;
}