POJ 2533 Longest Ordered Subsequence

题目链接：http://poj.org/problem?id=2533

Longest Ordered Subsequence

Time Limit: 2000MS Memory Limit: 65536KTotal Submissions: 35605 Accepted: 15621

Description

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_iK), 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

4

Source

Northeastern Europe 2002, Far-Eastern Subregion

题意:求最长上升子序列长度

题解:DP  这题我WA了两发.....~~~~(>_<)~~~~ 

AC代码:

#include<iostream>#include<cstring>#define N 1005using namespace std;int dp[N],num[N],n;int main(){    cin.sync_with_stdio(false);    while(cin>>n){        int res=1;        for(int i=0;i<n;i++)dp[i]=1;        for(int i=0;i<n;i++)cin>>num[i];        for(int i=1;i<n;i++){            for(int j=0;j<i;j++){                 if(num[i]>num[j])dp[i]=max(dp[i],dp[j]+1);                else if(num[i]==num[j])dp[i]=max(dp[i],dp[j]);            }            if(res<dp[i])res=dp[i];        }        cout<<res<<endl;    }    return 0;}