【杭电oj1159】Common Subsequence

太过爱你忘了你带给我的痛 2022-09-25 04:27 153阅读 0赞

# Common Subsequence #

**Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)  
Total Submission(s): 34234 Accepted Submission(s): 15611**

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.

Sample Input

abcfbc abfcab
    programming contest 
    abcd mnp

Sample Output

4
    2
    0

Source

[Southeastern Europe 2003][]

Recommend

Ignatius | We have carefully selected several similar problems for you: [1087][] [1003][] [1058][] [1069][] [2084][]

最长公共子序列模板题：

#include<cstdio>
    #include<iostream>
    #include<cstring>
    #include<cmath>
    using namespace std;
    const int N = 1000;
    char a[N],b[N];
    int dp[N][N];
    int main() {
        while(scanf("%s%s",&a,&b)!=EOF) {
            memset(dp,0,sizeof(dp));
            int lena=strlen(a);
            int lenb=strlen(b);
            for(int i=1; i<=lena; i++) {
                for(int j=1; j<=lenb; j++) {
                    if(a[i-1]==b[j-1])
                        dp[i][j]=dp[i-1][j-1]+1;
                    else
                        dp[i][j]=max(dp[i-1][j],dp[i][j-1]);
                }
            }
            printf("%d\n",dp[lena][lenb]);
        }
        return 0;
    }

[题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1159][http_acm.hdu.edu.cn_showproblem.php_pid_1159]

[Southeastern Europe 2003]: http://acm.hdu.edu.cn/search.php?field=problem&key=Southeastern+Europe+2003&source=1&searchmode=source
[1087]: http://acm.hdu.edu.cn/showproblem.php?pid=1087
[1003]: http://acm.hdu.edu.cn/showproblem.php?pid=1003
[1058]: http://acm.hdu.edu.cn/showproblem.php?pid=1058
[1069]: http://acm.hdu.edu.cn/showproblem.php?pid=1069
[2084]: http://acm.hdu.edu.cn/showproblem.php?pid=2084
[http_acm.hdu.edu.cn_showproblem.php_pid_1159]: http://acm.hdu.edu.cn/showproblem.php?pid=1159