D

来源：互联网发布：地球防卫少年知乎编辑：程序博客网时间：2024/04/24 04:40

A numeric sequence of a_i is ordered if a₁ < a₂ < ... < a_N. Let the subsequence of the given numeric sequence ( a₁, a₂, ..., a_N) be any sequence ( a_i₁, a_i₂, ..., a_{i_K}), where 1 <= i₁ < i₂ < ... < i_K <= N. For example, sequence (1, 7, 3, 5, 9, 4, 8) has ordered subsequences, e. g., (1, 7), (3, 4, 8) and many others. All longest ordered subsequences are of length 4, e. g., (1, 3, 5, 8).

Your program, when given the numeric sequence, must find the length of its longest ordered subsequence.

Input

The first line of input file contains the length of sequence N. The second line contains the elements of sequence - N integers in the range from 0 to 10000 each, separated by spaces. 1 <= N <= 1000

Output

Output file must contain a single integer - the length of the longest ordered subsequence of the given sequence.

Sample Input

71 7 3 5 9 4 8

Sample Output

题意：让你找出一个最长的子序列；

思路：动态规划之最长子序列问题（我博客里有，欢迎大家前去观看学习，哈哈^_^）；

下面附上代码：

#include<cstdio>#include<algorithm>#include<iostream>using namespace std;int a[1010],len[1010];int main(){int n,max,maxlen=1;for(int i=1;i<=10;i++)len[i]=1;cin>>n;for(int i=1;i<=n;i++)scanf("%d",&a[i]);for(int i=2;i<=n;i++){max=0;for(int j=1;j<=i-1;j++){if(a[j]<a[i]&&len[j]>max)max=len[j];}len[i]=max+1;if(len[i]>maxlen)maxlen=len[i];}printf("%d\n",maxlen);return 0;}