牛客网编程练习之编程马拉松：砌墙
思路其实很简单，无论再少的步骤，至少要能把矮的堆到平均高度，所以只求 sum(avg - (<avg))即可。
AC代码：
import java.util.Arrays;
import java.util.Scanner;
/**
* @author CC11001100
*/
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while (sc.hasNextInt()){
int n = sc.nextInt();
int[] stacks = new int[n];
for (int i = 0; i < n; i++) {
stacks[i] = sc.nextInt();
}
System.out.println(resolve(stacks));
}
}
private static int resolve(int[] n) {
int avg = (int) Arrays.stream(n).average().orElse(0);
return Arrays.stream(n).map(x -> x >= avg ? 0 : avg - x).sum();
}
}
