HDU - 1159(LCS)

最新推荐文章于 2025-04-03 17:46:53 发布

原创最新推荐文章于 2025-04-03 17:46:53 发布 · 224 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#算法

动态规划专栏收录该内容

4 篇文章

订阅专栏

本文介绍了一个寻找两个字符串之间最长公共子序列的算法问题，给出了AC代码实现。程序读取输入文件中的两组字符串，通过动态规划计算它们的最大公共子序列长度，并在标准输出中打印结果。示例输入和输出展示了算法的正确性。

Common Subsequence

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.
Input
abcfbc abfcab
programming contest
abcd mnp
Output
4
2
0
Sample Input
abcfbc abfcab
programming contest
abcd mnp
Sample Output
4
2
0

前言：

char a[100];
scanf("%s",a+1); //表示从数组a的首地址+1开始输入
cin>>a+1; //使用cin也可以这样写

AC代码

#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<iostream>
#include<cmath>
char s[1050],f[1050];
int dp[1050][1050];
using namespace std;
int main()
{
	
	while(~scanf("%s %s",s+1,f+1))
	{	
		int l1=strlen(s+1);
		int l2=strlen(f+1);
		memset(dp,0,sizeof(dp));
		for(int i=1;i<=l1;i++)
		{
			for(int j=1;j<=l2;j++)
			{
				if(s[i]==f[j])
				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[l1][l2]);
	}
 	return 0;
}