# 276. Paint Fence

There is a fence with n posts, each post can be painted with one of the k colors.

You have to paint all the posts such that no more than two adjacent fence posts have the same color.

Return the total number of ways you can paint the fence.

Note:
n and k are non-negative integers.

Example:

``````Input: n = 3, k = 2
Output: 6
Explanation: Take c1 as color 1, c2 as color 2. All possible ways are:

post1  post2  post3
-----      -----  -----  -----
1         c1     c1     c2
2         c1     c2     c1
3         c1     c2     c2
4         c2     c1     c1
5         c2     c1     c2
6         c2     c2     c1
``````

``````class Solution {
public:
int numWays(int n, int k) {
if (n == 0) return 0;
int same = 0, diff = k;
for (int i = 2; i <= n; ++i) {
int t = diff;
diff = (same + diff) * (k - 1);
same = t;
}
return same + diff;
}
};
``````

``````class Solution {
public:
int numWays(int n, int k) {
if (n == 0) return 0;
int same = 0, diff = k, res = same + diff;
for (int i = 2; i <= n; ++i) {
same = diff;
diff = res * (k - 1);
res = same + diff;
}
return res;
}
};
``````

Github 同步地址：

https://github.com/grandyang/leetcode/issues/276

House Robber II

House Robber

Paint House II

https://leetcode.com/problems/paint-fence/

https://leetcode.com/problems/paint-fence/discuss/71156/O(n)-time-java-solution-O(1)-space

https://leetcode.com/problems/paint-fence/discuss/178010/The-only-solution-you-need-to-read

LeetCode All in One 题目讲解汇总(持续更新中…)

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