HDU 1257 最少拦截系统

题目：http://acm.hdu.edu.cn/showproblem.php?pid=1257

贪心解法：

#include<stdio.h>
int a[3005],vist[3005];

int main()
{	
	int i,n,count,temp,j;
	while(scanf("%d",&n)!=EOF)
	{
		for(i=0;i<n;i++)
		{
			scanf("%d",&a[i]);
			vist[i] =0;
		}
		count = 0;
		for(i=0;i<n;i++)
		{
			if(!vist[i])
			{
				temp = a[i];
				count++;
				vist[i] = 1;
				for(j=i+1;j<n;j++)
				{
					if(a[j] <= temp && !vist[j] )
					{
						temp = a[j];
						vist[j]=1;
					}
				}
			}
		}
		printf("%d\n",count);
	}
	return 0;
}

求最长递增序列

#include<stdio.h>
int a[3005],dp[3005];

int main()
{	
	int i,n,res,j;
	freopen("a.txt","r",stdin);
	while(scanf("%d",&n)!=EOF)
	{
		for(i=0;i<n;i++)
			scanf("%d",&a[i]);
		res = -1;
		for(i=0;i<n;i++)
		{
			dp[i] = 1;	
			for(j=0;j<i;j++)
				if( a[i] > a[j] && dp[i] < dp[j]+1)
				{
					dp[i] = dp[j]+1;
					if ( dp[i] > res)
						res = dp[i];
				}
		}
		printf("%d\n",res);
	}
	return 0;
}