求数组中的最长递增子序列（编程之美2.16）

// 2_16.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#define INT_MIN -1000000;

int binary_search(int *a,int len,int n)//若返回值为x,则a[x]>=n>a[x-1]
{
	int left=0,right=len-1,mid=(left+right)/2;
    while(left<=right)
    {
        if(n>a[mid]) left=mid+1;
        else if(n<a[mid]) right=mid-1;
        else return mid;
        mid=(left+right)/2;
    }
    return left;

}

int LIS(int * arr, int len)
{
	int * max = new int[len+1];
	int * lis = new int[len];

	max[0] = INT_MIN;
	max[1] = arr[0];
	int maxLis = 1;
	for(int i=0;i<len;i++)
	{
		
		//遍历
		/*for(int j=maxLis;j>=0;j--)
		{
			if(arr[i] > max[j])
			{
				lis[i] = j+1;
				break;
			}
		}*/

		//二分查找
		lis[i] = binary_search(max,maxLis+1,arr[i]);

		if(lis[i] > maxLis)
		{
			max[lis[i]] = arr[i];
			maxLis = lis[i];
		}
		else if(max[lis[i]-1] < arr[i] && arr[i] < max[lis[i]])
		{
			max[lis[i]] = arr[i];
		}
	}

	delete [] max;
	delete [] lis;

	return maxLis;
}
int _tmain(int argc, _TCHAR* argv[])
{
	int arr[] = {1,2,5,4,6};

	printf("%d\n", LIS(arr,5));
	return 0;
}