算法导论—最长公共子序列

#include <iostream>
#include <vector>
#include <utility>
#include <string>
#include <utility>
using namespace std;

 
vector<vector<int>> lcsLen(const string &s1,const string &s2)
{
	int m=s1.size();
	int n=s2.size();
	vector<vector<int>> C(m+1,vector<int>(n+1));
	for(int i=1;i!=m+1;i++)
	{
		for(int j=1;j!=n+1;j++)
		{
			if(s1[i-1]==s2[j-1])
				C[i][j]=C[i-1][j-1]+1;
			else if(C[i-1][j]>=C[i][j-1])
				C[i][j]=C[i-1][j];
			else
				C[i][j]=C[i][j-1];

		}
	}
	return C;
}


int searchLcs(vector<vector<int>> &C,int i,int j,vector<pair<int,int>> &pos)
{

	if(i==0||j==0)
		return -1;
	if ((C[i][j]>C[i-1][j])&&(C[i][j]>C[i][j-1]))
	{
		searchLcs(C,i-1,j-1,pos);
		pos.push_back(make_pair(i-1,j-1));
	}
	else if(C[i][j]==C[i-1][j])
		searchLcs(C,i-1,j,pos);
	else
		searchLcs(C,i,j-1,pos);
	return 0;
}

int printLcs(const string &s1,const string &s2)
{
	vector<vector<int>> C=lcsLen(s1,s2);
	vector<pair<int,int>> pos;
	int m=s1.size();
	int n=s2.size();
	searchLcs(C,m,n,pos);
	cout<<"S1 is :"<<s1<<endl;
	cout<<"S2 is :"<<s2<<endl;
	cout<<"The length of Common subseqence is:"<<C[m][n]<<endl;
	for(auto p:pos)
		cout<<s1[p.first]<<" in S1: "<<p.first<<" in S2: "<<p.second<<endl;
	return 0;
}

测试文件：

#include <vector>
#include <iostream>
#include "LCS.h"

using namespace std;
int main()
{
	string s1="ABCBDAB";
	string s2="BDCABA";
	printLcs(s1,s2);

}