rotate-array.cpp

// Given an array, rotate the array to the right by k steps, where k is non-negative.
//
// 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]
//
//
// Note:
//
//
// 	Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.
// 	Could you do it in-place with O(1) extra space?
//
//


class Solution {
public:
    void rotate(vector<int>& nums, int k) {
        int len = nums.size();
        k %= len;
        reverse(nums.begin(), nums.begin()+len-k);
        reverse(nums.begin()+len-k, nums.end());
        reverse(nums.begin(), nums.end());
    }
};