题解 | #数的选择#

import java.util.Arrays;
import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        long num = Long.parseLong(scanner.next());
        long[] list = new long[(int) (num+1)];
        for (int i = 1; i <= num; i++) {
            list[i] = Long.parseLong(scanner.next());
        }
        Arrays.sort(list);
        long[] preSum = new long[(int) (num+2)];
        for (int i = (int) num; i >= 1; i--) {
            preSum[i] = preSum[i+1] + list[i];
        }
        boolean ifMatch = true;
        for (int i = (int) num; i >= 1; i--) {
            if (num+3-i <= num + 1) {
                if (preSum[i] > preSum[1] - preSum[(int) (num+3-i)]) {
                    System.out.println(num - i + 1);
                    ifMatch = false;
                    break;
                }
            }
        }
        if (ifMatch) System.out.println("-1");
    }
}