描述
Given an array, rotate the array to the right by k steps, where k is non-negative.
1.Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.
2.Could you do it in-place with O(1) extra space?
您在真实的面试中是否遇到过这个题？
是
样例
Example 1:
Input: [1,2,3,4,5,6,7] and k = 3
Output: [5,6,7,1,2,3,4]
Explanation:
rotate 1 steps to the right: [7,1,2,3,4,5,6]
rotate 2 steps to the right: [6,7,1,2,3,4,5]
rotate 3 steps to the right: [5,6,7,1,2,3,4]
Example 2:
Input: [-1,-100,3,99] and k = 2
Output: [3,99,-1,-100]
Explanation:
rotate 1 steps to the right: [99,-1,-100,3]
rotate 2 steps to the right: [3,99,-1,-100]这道题很像第8题，https://blog.csdn.net/vestlee/article/details/80332709
class Solution {
public:
/**
* @param nums: an array
* @param k: an integer
* @return: rotate the array to the right by k steps
*/
vector<int> rotate(vector<int> &nums, int k) {
// Write your code here
if (nums.empty() || (k %= nums.size()) == 0) return nums;
int n = nums.size(), start = 0, i = 0, cur = nums[i], cnt = 0;
while (cnt++ < n) {
i = (i + k) % n;
int t = nums[i];
nums[i] = cur;
if (i == start) {
++start;
++i;
cur = nums[i];
} else cur = t;
}
return nums;
}
};参考博客：
http://www.cnblogs.com/grandyang/p/4298711.html