标签：
Rotate an array of n elements to the right by k steps.
For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4].
Note:
Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.
1 class Solution { 2 public: 3 void rotate(int nums[], int n, int k) { 4 if (nums == NULL || n <= 0 || k <= 0) 5 return; 6 k %= n; 7 reverse(nums, 0, n - 1); 8 reverse(nums, 0, k - 1); 9 reverse(nums, k, n - 1); 10 } 11 12 void reverse(int nums[], int begin, int end) { 13 if (begin >= end) return; 14 while (begin < end) { 15 swap(nums[begin++], nums[end--]); 16 } 17 } 18 };
解法2：参考https://oj.leetcode.com/discuss/26088/solutions-with-extra-memory-dont-know-the-third-one-yet-idea的answer
1 class Solution { 2 public: 3 void rotate(int nums[], int n, int k) { 4 if (nums == NULL || n <=0 || k <= 0) 5 return; 6 k %= n; 7 int index = 0; 8 int cycle = 0; 9 int next = 0; 10 int temp = nums[next]; 11 for (int i = 0; i < n; ++i) { 12 next = (next + k) % n; 13 swap(nums[next], temp); 14 if (cycle == next) { 15 next++; 16 cycle = next; 17 temp = nums[next]; 18 } 19 } 20 } 21 };
标签：
原文地址：http://www.cnblogs.com/vincently/p/4299924.html
