算法训练 区间k大数查询（数组复制、排序算法、递归查找）

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

public class Main {

	/**
	 * @param args
	 */

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] a = new int[n];
		for (int i = 0; i < n; i++)
			a[i] = sc.nextInt();
		int m = sc.nextInt();
		while (m-- > 0) {
			int l = sc.nextInt();
			int r = sc.nextInt();
			int k = sc.nextInt();
			int length = r - l + 1;
			int[] b = new int[length];
			System.arraycopy(a,l - 1,b,length);
			Arrays.sort(b);
			System.out.println(b[length - k]);
		}
	}
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

	/**
	 * @param args
	 * @throws IOException
	 * @throws
	 */

	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		String[] s = br.readLine().split(" ");
		int[] arr = new int[n + 1];
		for (int i = 1; i < n + 1; i++) {
			arr[i] = Integer.parseInt(s[i - 1]);
		}
		int m = Integer.parseInt(br.readLine());
		for (int i = 0; i < m; i++) {
			String[] s1 = br.readLine().split(" ");
			int l = Integer.parseInt(s1[0]);
			int r = Integer.parseInt(s1[1]);
			int k = Integer.parseInt(s1[2]);
			int size = r - l + 1;
			int[] brr = new int[size + 1];
			System.arraycopy(arr,l,brr,1,size);
			int result = SelectMaxK(brr,size,k);
			System.out.println(result);
		}
	}

	private static int SelectMaxK(int[] brr,int low,int high,int k) {
		// TODO Auto-generated method stub
		int s = Partition(brr,low,high);
		if (s == k)
			return brr[s];
		if (k < s)
			return SelectMaxK(brr,s - 1,k);

		return SelectMaxK(brr,s + 1,high,k);

	}

	private static int Partition(int[] brr,int high) {
		// TODO Auto-generated method stub
		int i = low;
		int j = high;
		while (i < j) {
			while (i < j && brr[i] >= brr[j])
				j--;
			if (i < j) {
				int temp = brr[i];
				brr[i] = brr[j];
				brr[j] = temp;
				i++;
			}
			while (i < j && brr[i] >= brr[j])
				i++;
			if (i < j) {
				int temp = brr[i];
				brr[i] = brr[j];
				brr[j] = temp;
				j--;
			}
		}
		return i;
	}

}