计算最大次大值的最优算法

/*
/**求最大，次大值，比较次数为：n + log n -2 ,n-1 为求最大值的代价，log n -1 为求次大值的代价。
*/

public class SubmaxAndMaxEfficient
{
static int Max, Submax;
int max(int a, int b) //取a, b 最大值
{
if (a > b)
return a;
else
return b;
}

void heapFindMax(int[] E, int n)
{
int last;
int[] array = new int[2 * n];

// 把原数组放到array[n...2*n-1]
for (int i = 2 * n - 1, j = n - 1; i >= n; i--) {
array[i] = E[j--];
}
//找最大值，放到array[1]
for (last = 2 * n - 2; last >= 2; last -= 2) {
array[last / 2] = max(array[last], array[last + 1]);
}
Max = array[1];
if (array[2] > array[3])
Submax = array[3];
else
Submax = array[2];
//沿着堆顶往下找次大值
for (int i = 2; i <= 2 * n - 1; i *= 2) {
if (array[i] < array[i + 1]) {
Submax = max(array[i], Submax);
i += 1;
} else
Submax = max(array[i + 1], Submax);
}
}
public static void main(String[] args)
{
SubmaxAndMaxEfficient Result = new SubmaxAndMaxEfficient();
int[] array = new int[] {
102, -3, -4, -2, -6, 0,-4, 100, 1, 2, 3, 4, 5, 6, 7, 8,101};
for (int i = 0; i < array.length; i++) {
System.out.println(array[i]);
}
Result.heapFindMax(array, 17);
System.out.println("Max is: " + Max);
System.out.println("Submax is: " + Submax);
}
}