利用递归方法求一个数组的最大值

1、直接利用递归:

package programmer;

import java.util.Scanner;

/*
 * 利用递归算法求最大值
 */
public class MaxRecursion {
	public int maxRecursion(int[] A, int low, int high) {
		if (low > high)
			return -1;
		else {
			if (A[low] < maxRecursion(A, low + 1, high))
				return maxRecursion(A, low + 1, high);
			else
				return A[low];
		}
	}

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int[] A = new int[N];
		for (int i = 0; i < A.length; i++)
			A[i] = sc.nextInt();
		System.out.println(new MaxRecursion().maxRecursion(A, 0, A.length - 1));
	}
}


2、利用二叉查找寻找数组中的最大值:

package programmer;

import java.util.Scanner;

/*
 * 利用二分查找法递归寻找数组中的最大值
 */
public class MaxBinarySearch {
	public int maxBinarySearch(int[] A, int low, int high) {
		if (low > high)
			return -1;
		else {
			int mid = (low + high) / 2;
			int tmp = maxBinarySearch(A, low, mid - 1) > maxBinarySearch(A,
					mid + 1, high) ? maxBinarySearch(A, low, mid - 1)
					: maxBinarySearch(A, mid + 1, high);
			return tmp > A[mid] ? tmp : A[mid];
		}
	}

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int[] A = new int[N];
		for (int i = 0; i < A.length; i++)
			A[i] = sc.nextInt();
		System.out.println(new MaxBinarySearch().maxBinarySearch(A, 0,
				A.length - 1));
	}
}

但是复杂度并没有减少,只是提供一种新的思考方法。

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