LeetCode:Rotate Array
Problem:
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.
Solution:问题意思是要将末尾的数字依次右移 总共移动三次 则是左移n-k%n 采用三步反转。
1 class Solution { 2 public: 3 void rotate(vector<int>& nums, int k) { 4 int n=nums.size(); 5 int m=n-k%n; 6 reverse(nums,0,m-1); 7 reverse(nums,m,n-1); 8 reverse(nums,0,n-1); 9 10 } 11 void reverse(vector<int>& nums,int from,int to) 12 { 13 while(from<to) 14 { 15 int temp=nums[from]; 16 nums[from++]=nums[to]; 17 nums[to--]=temp; 18 } 19 } 20 };