Question

link

输入一个数组,要求输出满足:a[0]<=a[1]>=a[2]<=a[3]>=…

Solution

O(n),一边扫描即可。发现不符合条件的只要跟前面一个数对调就可以,

Code

public int[] solve(int[] input) {
    boolean incr = true;
    int len = input.length;
    int p = 1;
    while (p < len) {
        if (incr ^ (input[p - 1] < input[p])) {
            Common.swap(input, p - 1, p);
        }
        p++;
        incr = !incr;
    }
    return input;
}