标签：
Description
Input
Output
Sample Input
7 1 7 3 5 9 4 8
Sample Output
4
题目大意：
给你一个长度为n的字符串，让你求出这个串的最长的子序列。
解题思路：
常见的dp题型：LIS
定义状态：dp[i]表示以a[i]结尾的最长上升子序列的长度
初始状态：dp[i] = 1
状态转移方程：dp[i] = max(dp[i],dp[j]+1 );&&(j < i,a[j] <a[i] )的情况下。
代码：
1 # include<cstdio> 2 # include<iostream> 3 # include<fstream> 4 # include<algorithm> 5 # include<functional> 6 # include<cstring> 7 # include<string> 8 # include<cstdlib> 9 # include<iomanip> 10 # include<numeric> 11 # include<cctype> 12 # include<cmath> 13 # include<ctime> 14 # include<queue> 15 # include<stack> 16 # include<list> 17 # include<set> 18 # include<map> 19 20 using namespace std; 21 22 const double PI=4.0*atan(1.0); 23 24 typedef long long LL; 25 typedef unsigned long long ULL; 26 27 # define inf 999999999 28 # define MAX 10000+4 29 30 int a[MAX]; 31 int dp[MAX]; 32 33 34 int main(void) 35 { 36 int n; 37 while ( scanf("%d",&n)!=EOF ) 38 { 39 int res = -1; 40 for ( int i = 0;i < n;i++ ) 41 { 42 scanf("%d",&a[i]); 43 } 44 for ( int i = 0;i < n;i++ ) 45 { 46 dp[i] = 1; 47 for ( int j = 0;j < i;j++ ) 48 { 49 if ( a[j] < a[i] ) 50 { 51 dp[i] = max(dp[i],dp[j]+1 ); 52 } 53 } 54 res = max(res,dp[i]); 55 } 56 printf("%d\n",res); 57 } 58 59 60 return 0; 61 }
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原文地址：http://www.cnblogs.com/wikioibai/p/4430752.html
