蓝桥杯（3.17 刷真题）

1240. 完全二叉树的权值
P8681 蓝桥杯 2019 省 AB 完全二叉树的权值
AC

import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] res = new int[n+1];
		for(int i=1;i<=n;i++) {
			res[i] = sc.nextInt();
		}
		int cs = 1;
		long MAX = Long.MIN_VALUE;
		int key = 0;
		int t = 1;
		for(int i=1;i<=n;i*=2,cs++,t*=2) {
			int w = t;
			long sum = 0;
			for(int j=i;j<=n&&t!=0;j++,t--) {
				sum+=res[j];
			}
			if(sum>MAX) {
				MAX = sum;
				key = cs;
			}
			t = w;
		}
		System.out.println(key);
	}
}