Note: This is an extension of House Robber.
After robbing those houses on that street, the thief has found himself a new place for his thievery so that he will not get too much attention. This time, all houses at this place are arranged in a circle. That means the first house is the neighbor of the last one. Meanwhile, the security system for these houses remain the same as for those in the previous street.
Given a list of non-negative integers representing the amount of money of each house, determine the maximum amount of money you can rob tonight without alerting the police.
只是这次变成了一个环，那么只要把数组分成两个：不包括第一个元素、不包括最后一个元素，就可以把环拆掉。取House Robber的最大值。
代码语言：javascript复制 public int rob(int[] nums) {
if (nums == null || nums.length == 0) {
return 0;
}
if (nums.length == 1) {
return nums[0];
}
if (nums.length == 2) {
return Math.max(nums[0], nums[1]);
}
return Math.max(help(Arrays.copyOfRange(nums, 0, nums.length - 1)),
help(Arrays.copyOfRange(nums, 1, nums.length)));
}
public int help(int[] nums) {
if (nums.length == 0) {
return 0;
}
if (nums.length == 1) {
return nums[0];
}
int[] P = new int[nums.length];
P[0] = nums[0];
P[1] = Math.max(nums[0], nums[1]);
for (int i = 2; i < nums.length; i ) {
P[i] = Math.max(nums[i] P[i - 2], P[i - 1]);
}
return P[nums.length - 1];
}
