LeetCode189——Rotate Array两种解法（一种易读，一种高效）

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.

[show hint]

Credits: Special thanks to @Freezen for adding this problem and creating all test cases.

难度系数：

容易

实现

void rotate(int nums[], int n, int k) {
    int temp;
    for (int step = 0; step < k; step++) {
        temp = nums[n-1];
        for (int i = n-1; i > 0; --i)
        {
            nums[i] = nums[i-1];
        }
        nums[0] = temp;
    }
}

上面这个实现，很好理解，但是正如评论里说的，运行效率不高。下面这个的效率有极大的提升：

void rotate(int nums[], int n, int k) {
    k = k % n;
    if (k == 0) return;
    int *temp = new int[n];
    memcpy(temp, nums+(n-k), sizeof(int)*k);
    memcpy(temp+k, nums, sizeof(int)*(n-k));
    memcpy(nums, temp, sizeof(int)*n);
    delete[] temp;
}