Go: package main

import (
	"bufio"
	"os"
	"strconv"
	"fmt"
)

func max(x, y int) int {
	if x < y {
		return y
	} else {
		return x
	}
}

/*********************************************************************
長さmの列X_(m)と長さnの列Y_(n)の最長共通部分列LCSは、
	(1)X[m] == Y[n]ならば、X_(m-1)とY_(n-1)のLCSにX[m]を繋げたもの
	(2)X[m] != Y[n]ならば、X_(m-1)とY_(n)のLCSもしくはX_(m)とY_(n-1)のLCS
	のいずれかのうち長い方

c[m+1][n+1]：c[i][j]にX_(i)とY_(j)のLCSの長さを格納する二次元配列
*********************************************************************/

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Scan()
	n, _ := strconv.Atoi(scanner.Text())
	for i := 0; i < n; i++ {
		scanner.Scan()
		s1 := scanner.Text()
		scanner.Scan()
		s2 := scanner.Text()
		s1, s2 = s1 + " ", s2 + " "
		c := make([][]int, len(s1))
		for i := range c {
			c[i] = make([]int, len(s2))
		}

		LCS := 0

		for i := 1; i < len(s1); i++ {
			for j := 1; j < len(s2); j++ {
				if s1[i] == s2[j] {
					c[i][j] = c[i-1][j-1] + 1
				} else {
					c[i][j] = max(c[i-1][j], c[i][j-1])
				}
				LCS = max(LCS, c[i][j])
			}
		}
		fmt.Println(LCS)
	}
}

C++: #include<iostream>
#include<cstdio>
#include<string>
using namespace std;

#define MAX_N 1000
#define MAX_M 1000

void solve();

string s, t;
int dp[MAX_N + 1][MAX_M + 1];

void solve(){
	for(int i = 0; i < s.length(); i++){
		for(int j = 0; j < t.length(); j++){
			if(s[i] == t[j]){
				dp[i + 1][j + 1];
					dp[i + 1][j + 1] = dp[i][j] + 1;
				} else {
					dp[i + 1][j + 1] = max(dp[i][j], dp[i + 1][j]);
				}
			}
		}
		cout << dp[s.length()][t.length()] << endl;
}

int main(){
	int n;
	cin >> n;
	for(int i = 0; i < n; i++){
		cin >> s >> t;
		solve();
	}
	return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
using namespace std;

static const int N = 1000;

int lcs(string x, string y) {
  int c[N + 1][N + 1];
  int m = x.size();
  int n = y.size();
  int maxl = 0;
  x = ' ' + x;
  y = ' ' + y;
  for ( int i = 1; i <= m; i++ ) c[i][0] = 0;
  for ( int j = 1; j <= n; j++ ) c[0][j] = 0;

  for ( int i = 1; i <= m; i++ ) {
    for ( int j = 1; j <= n; j++ ) {
      if ( x[i] == y[j] ) {
        c[i][j] = c[i - 1][j - 1] + 1;
      } else {
        c[i][j] = max(c[i - 1][j], c[i][j - 1]);
      }
      maxl = max(maxl, c[i][j]);
    }
  }

  return maxl;
}

int main() {
  string s1, s2;
  int q;
  cin >> q;

  for ( int i = 0; i < q; i++ ) {
    cin >> s1 >> s2;
    cout << lcs(s1, s2) << endl;
  }

  return 0;
}

C++: #include<iostream>
#include<string>
#include<string.h>

using namespace std;

int lcs(char x[],char y[]);

int main(){
	char x[1000],y[1000];
	int n,*memo; cin>>n;
	memo = new int[n];
	for(int i=0;i<n;i++){
		cin>>x>>y;
		memo[i] = lcs(x,y);
	}
	for(int i=0;i<n;i++)
		cout<<memo[i]<<endl;

	delete [] memo;
}

int lcs(char x[],char y[]){
	int m = strlen(x), n = strlen(y);
	int **c,a;
	c = new int*[m+1]; for(int i=0;i<=m;i++) c[i] = new int[n+1];
	for(int i=0;i<=m;i++) c[i][0] = 0;
	for(int j=1;j<=n;j++) c[0][j] = 0;
	for(int i=1;i<=m;i++){
		for(int j=1;j<=n;j++){
			if(x[i-1]==y[j-1]){
				c[i][j] = c[i-1][j-1]+1;
				if(i==m&&j==n){
					a = c[i][j];
					//cout<<c[i][j]<<endl;
				}
			}else{
				if(c[i-1][j]>=c[i][j-1]){
					c[i][j] = c[i-1][j];
					if(i==m&&j==n){
						a = c[i][j];
						//cout<<c[i][j]<<endl;
					}
				}else{
					c[i][j] = c[i][j-1];
					if(i==m&&j==n){
						a = c[i][j];
						//cout<<c[i][j]<<endl;
					}
				}
			}
		}
	}
	for(int i=0;i<=strlen(x);i++) delete [] c[i]; delete [] c;
	return a;
}

C++: #include<bits/stdc++.h>
using namespace std;

int lcs(string X,string Y){
  int c[1001][1001];
  int m = X.size();
  int n = Y.size();
  int maxl = 0;
  X = ' ' + X;
  Y = ' ' + Y;
  for(int i=0;i<=m;i++) c[i][0]=0;
  for(int j=1;j<=n;j++) c[0][j]=0;
  for(int i=1;i<=m;i++){
    for(int j=1;j<=n;j++){
      if(X[i]==Y[j]) c[i][j]=c[i-1][j-1]+1;
      else c[i][j]=max(c[i-1][j],c[i][j-1]);
      maxl=max(maxl,c[i][j]);
    }
  }
  return maxl;
}

int main(){
  int q;cin>>q;
  while(q--){
    string a,b;cin>>a>>b;
    cout<<lcs(a,b)<<endl;
  }
  return 0;
}

C++: #include <iostream>
#include <string>

using namespace std;

int q;
string A, B;

void findlongest() {
	int res[1001][1001];
	A = ' '+A ;
	B = ' '+B ;
	int l1 = A.size();
	int l2 = B.size();
	int max = 0;
	int j;
	for (int i = 0; i < l1; ++i) {
		for (j = 0; j < l2; ++j) {
			if (i == 0) {
				res[0][j] = 0;
			}
			else if (j == 0) {
				res[i][0] = 0;
			}
			else {
				if (A[i] == B[j]) {
					res[i][j] = res[i - 1][j - 1] + 1;
					if (max < res[i][j]) {
						max = res[i][j];
					}
				}
				else {
					if (res[i - 1][j] >= res[i][j - 1]) {
						res[i][j] = res[i - 1][j];
					}
					else {
						res[i][j] = res[i][j - 1];
					}
				}
			}
			//cout << res[i][j] << ' ';
		}
		//cout << endl;
	}

	cout << max << endl;
}

int main() {
	cin >> q;
	for (int i = 0; i < q; ++i) {
		cin >> A;
		cin >> B;
		findlongest();
	}
	return 0;
}

C++: #include<iostream>
#include<map>
#include<vector>
#include<algorithm>
#include<cmath>
#include<climits>
#include<ctime>
#include<cstring>
#include<numeric>

#define ALL(v) (v).begin(),(v).end()
#define REP(i,p,n) for(int i=p;i<(int)(n);++i)
#define rep(i,n) REP(i,0,n)
#define dump(a) (cerr << #a << "=" << (a) << endl)
#define DUMP(list) cout << "{ "; for(auto nth : list){ cout << nth << " "; } cout << "}" << endl;

using namespace std;

const int INF = 100000000;

int main() {
	int N;
	cin >> N;
	rep(i, N) {
		string s1, s2;
		cin >> s1 >> s2;
		int n = s1.size();
		int m = s2.size();
		vector<vector<int>> dp(n+1, vector<int>(m+1, 0));
		dp[0][0] = 0;
		for(int i = 1; i <= n; ++i) {
			for(int j = 1; j <= m; ++j) {
				if(s1[i-1] == s2[j-1]) {
					dp[i][j] = dp[i-1][j-1] + 1;
				} else {
					dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
				}	
			}
		}
		cout << dp[n][m] << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <climits>
#include <cmath>
#include <algorithm>
#include <utility>
#include <vector>
#include <string>

#define MAX 200000
#define INFTY 1<<30

using namespace std;

static const int N = 1000;

int lcs(string X, string Y)
{
  int dp[N+1][N+1];
  int m = X.size();
  int n = Y.size();
  int maxl = 0;

  X = ' ' + X;
  Y = ' ' + Y;
  for(int i = 0; i < m; i++) dp[i][0] = 0;
  for(int j = 0; j < n; j++) dp[0][j] = 0;

  for(int i = 1; i <= m; i++)
  {
    for(int j = 1; j <= n; j++)
    {
      if(X[i] == Y[j])
        dp[i][j] = dp[i-1][j-1] + 1;
      else
        dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
      maxl = max(maxl,dp[i][j]);
    }
  }
  return maxl;
}

int main()
{
  int n; cin >> n;
  string s1, s2;
  for(int i = 0; i < n; i++)
  {
    cin >> s1 >> s2;
    cout << lcs(s1,s2) << endl;
  }
  return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;

int main(){
  int n;
  char x[1001],y[1001];
  int dp[1002][1002];
  


  //load n;
  cin >>n;
  for(int i=0;i<n;i++){
    //initialize
    for(int i=0;i<1002;i++){
      for(int j=0;j<1002;j++){
	dp[i][j]=0; 
      }
    }
    //load string
    scanf("%s",x);
    scanf("%s",y);
    //dp
    for(int j=0;j<strlen(x);j++){
      for(int k=0;k<strlen(y);k++){
	if(x[j]==y[k]){
	  dp[j+1][k+1]=dp[j][k]+1;
	}

	else{
 
	  if(dp[j][k+1]>dp[j+1][k]){
	    dp[j+1][k+1]=dp[j][k+1];
	  }

	  else{
	    dp[j+1][k+1]=dp[j+1][k];
	  }
	}
      }
    }

    //print
    cout <<dp[strlen(x)][strlen(y)]<<endl;
  }



  return 0;
}