0189-rotate-array.java

class Solution {
    public void rotate(int[] nums, int k) {
        //Do not return anything, modify nums in-place instead
        k = k % nums.length;
        int l = 0, r = nums.length - 1;
        while(l < r) {
            int tmp = nums[l];
            nums[l] = nums[r];
            nums[r] = tmp;
            l += 1;
            r -= 1;
        }
        l = 0;
        r = k - 1;
        while(l < r) {
            int tmp = nums[l];
            nums[l] = nums[r];
            nums[r] = tmp;
            l += 1;
            r -= 1;
        }
        l = k;
        r = nums.length - 1;
        while(l < r) {
            int tmp = nums[l];
            nums[l] = nums[r];
            nums[r] = tmp;
            l += 1;
            r -= 1;
        }
    }
}