编程之美 2.16

import java.util.*;
public class Main{
    public static void main(String[] args) {
        int[] nums={1,-1,2,-3,4,-5,6,-7};
        int len=nums.length;
        int[] maxNum=new int[len+1];
        maxNum[1]=nums[0];
        maxNum[0]=Integer.MIN_VALUE;
        int maxLength=1;
        for(int i=1;i<len;i++){
            int temp=1;
            int start=0;
            int end=maxLength;
            if(nums[i]>maxNum[end]){
                maxLength=end+1;
                maxNum[maxLength]=nums[i];
                continue;
            }
            while(start<=end){
                int mid=start+(end-start)/2;
                if(maxNum[mid]>nums[i]){
                    end=mid-1;
                }else if(maxNum[mid]<nums[i]){
                    start=mid+1;
                }else{
                    break;
                }
            }
            if(start<=end){
                continue;
            }else if(nums[i]>maxNum[end] && nums[i]<maxNum[start])
            {
                temp=end+1;
                maxNum[temp]=nums[i];
            }                
        }
        System.out.println(maxLength);
    }
}