面接問題の収集(20)(配列の最大値と二次最大値をとる)

public class GetMax {

	public static void main(String[] args) {
		int[] nums = { 2, 3, 4, 1, 2 };
		System.out.println(getMax(nums));
		System.out.println(getPerMax(nums));
	}

	/**
	 *   
	 */
	public static int getMax(int[] nums) {

		int max = Integer.MIN_VALUE;
		if (nums == null || nums.length == 0) {
			throw new NullPointerException(
					"the array is null or length less than 1");
		}

		max = nums[0];

		for (int i = 1; i < nums.length; i++) {

			if (nums[i] > max)
				max = nums[i];
		}

		return max;
	}

	/**
	 *  
	 */
	public static int getPerMax(int[] nums) {

		int max = Integer.MIN_VALUE;
		int perMax = Integer.MIN_VALUE;

		if (nums == null || nums.length < 2) {
			throw new NullPointerException(
					"the array is null or length less than 2");
		}
		max = nums[0];
		for (int i = 1; i < nums.length; i++) {

			if (nums[i] > max)
				max = nums[i];
		}

		for (int i = 0; i < nums.length; i++) {
			if (nums[i] > perMax && nums[i] < max) {
				perMax = nums[i];
			}
		}
		if (max == perMax)
			throw new RuntimeException("no secord number.");
		return perMax;
	}

}