Leetcode|取余+数组翻转|189. 旋转数组

class Solution {
public:
    void reverse(vector<int>& nums, int left, int right) {
        while (left < right) {
            swap(nums[left], nums[right]);
            left++; right--;
        }
    }

    void rotate(vector<int>& nums, int k) {
        int size = nums.size();
        // 1.翻转全部数组，将后k个元素翻转到前面
        reverse(nums, 0, size - 1);
        // 2.翻转前(k % size)元素，保证排序
        reverse(nums, 0, (k % size) - 1);
        // 2.翻转后size - (k % size)元素
        reverse(nums, (k % size), size - 1);
    }
};

class Solution {
public:
    void rotate(vector<int>& nums, int k) {
        vector<int> res;
        int size = nums.size();
        // 后k个元素添加
        for (int i = size - (k % size); i < size; i++)
            res.emplace_back(nums[i]);
        // 前size - k个元素添加
        for (int i = 0; i < size - (k % size); i++)
            res.emplace_back(nums[i]);
        nums = res;
    }
};