java面试题（6）

原题：

// 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.

答案：

public class Solution {    public int numWays(int n, int k) {        if(n <= 0) {            return 0;        }        int sameColorCounts = 0;        int differentColorCounts = k;        for(int i = 2; i <= n; i++) {            int temp = differentColorCounts;            differentColorCounts = (sameColorCounts + differentColorCounts) * (k - 1);            sameColorCounts = temp;        }        return sameColorCounts + differentColorCounts;    }}