hdu1159
Common Subsequence
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 43355 Accepted Submission(s): 20013
Problem Description
A subsequence of a given sequence is the given sequence with some elements (possible none) left out. Given a sequence X = <x1, x2, ..., xm> another sequence Z = <z1, z2, ..., zk> is a subsequence of X if there exists a strictly increasing sequence <i1, i2, ..., ik> of indices of X such that for all j = 1,2,...,k, xij = zj. For example, Z = <a, b, f, c> is a subsequence of X = <a, b, c, f, b, c> with index sequence <1, 2, 4, 6>. Given two sequences X and Y the problem is to find the length of the maximum-length common subsequence of X and Y.
The program input is from a text file. Each data set in the file contains two strings representing the given sequences. The sequences are separated by any number of white spaces. The input data are correct. For each set of data the program prints on the standard output the length of the maximum-length common subsequence from the beginning of a separate line.
The program input is from a text file. Each data set in the file contains two strings representing the given sequences. The sequences are separated by any number of white spaces. The input data are correct. For each set of data the program prints on the standard output the length of the maximum-length common subsequence from the beginning of a separate line.
Sample Input
abcfbc abfcab
programming contest
abcd mnp
Sample Output
4
2
0
分析:动态规划。c[i][j]记录"x0,x1, ...,xn-2"与"y0, y1, ..., yn-2"的最长公共子序列的长度,
递推公式如下:
#include<cstdio> #include<cstring> #include<algorithm> using namespace std; char a[2000],b[2000]; int dp[1000][1000]; int main() { while(scanf("%s%s",a,b)!=EOF) { memset(dp,0,sizeof(dp)); int N=strlen(a),M=strlen(b); for(int i=0;i<N;i++) { for(int j=0;j<M;j++) if(a[i]==b[j]) dp[i+1][j+1]=dp[i][j]+1; else dp[i+1][j+1]=max(dp[i][j+1],dp[i+1][j]); } printf("%d\n",dp[N][M]); } return 0; }
作者:ACRykl —— O ever youthful,O ever weeping!
出处:http://www.cnblogs.com/ACRykl/
本文版权归作者和博客园共有,欢迎转载,但未经作者同意必须保留此段声明,且在文章页面明显位置给出原文连接,否则保留追究法律责任的权利。
【推荐】编程新体验,更懂你的AI,立即体验豆包MarsCode编程助手
【推荐】凌霞软件回馈社区,博客园 & 1Panel & Halo 联合会员上线
【推荐】抖音旗下AI助手豆包,你的智能百科全书,全免费不限次数
【推荐】轻量又高性能的 SSH 工具 IShell:AI 加持,快人一步