RotateArray.java

package com.leetcode;

/**
 * Created by jamylu on 2018/1/7.
 * leetcode189.
 * Rotate an array of n elements to the right by k steps.
 */
public class RotateArray {
    public static void main(String[] args) {
        int nums[] = {1, 2, 3, 4, 5, 6, 7};
        int k = 8;
        rotate(nums, k);
        for (int i = 0; i < nums.length; i++) {
            System.out.print(nums[i] + " ");
        }
    }

    //将数组进行转置
    public static void rotate(int[] nums, int k) {
        k %= nums.length;
        reverse(nums, 0, nums.length - 1);
        reverse(nums, 0, k - 1);
        reverse(nums, k, nums.length - 1);
    }

    public static void reverse(int[] nums, int start, int end) {
        while (start < end) {
            int tmp = nums[start];
            nums[start] = nums[end];
            nums[end] = tmp;
            start++;
            end--;
        }
    }
}