Go: package main

/*
最長共通部分列
*/

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"os"
	"strconv"
	"strings"
)

func larger(l, r int) int {
	if l > r {
		return l
	}
	return r
}

var memo [1001][1001]int

func countLCS(x, y string) int {
	x = " " + x
	y = " " + y
	max := 0
	for xi := 1; xi < len(x); xi++ {
		for yi := 1; yi < len(y); yi++ {
			if x[xi] == y[yi] {
				memo[xi][yi] = memo[xi-1][yi-1] + 1
			} else {
				memo[xi][yi] = larger(memo[xi-1][yi], memo[xi][yi-1])
			}
			max = larger(max, memo[xi][yi])
		}
	}
	return max
}

func main() {
	scanner := makeScanner(1024)
	q := eGetInt(scanner)
	for i := 0; i < q; i++ {
		x := eGetLine(scanner)
		y := eGetLine(scanner)
		fmt.Println(countLCS(x, y))
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

type ints []int

func (s ints) String() string {
	var buf bytes.Buffer
	buf.WriteString("[")
	sep := ""
	for _, v := range s {
		buf.WriteString(fmt.Sprintf("%s%d", sep, v))
		sep = ", "
	}
	buf.WriteString("]")
	return buf.String()
}

func reverse(a ints) ints {
	r := make(ints, len(a))
	for i := 0; i < len(a); i++ {
		r[i] = a[len(a)-1-i]
	}
	return r
}
func max(a ints) (int, bool) {
	if len(a) == 0 {
		return 0, false
	}
	m := a[0]
	for _, e := range a {
		if e > m {
			m = e
		}
	}
	return m, true
}
func min(a []int) int {
	m := a[0]
	for _, v := range a {
		if v < m {
			m = v
		}
	}
	return m
}

func sum(a ints) int {
	if len(a) == 0 {
		return 0
	}
	sum := 0
	for _, e := range a {
		sum += e
	}
	return sum
}
func find(n int, a ints) int {
	for i, v := range a {
		if n == v {
			return i
		}
	}
	return -1
}

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

C++: #include <iostream>
#include <string>
#include <cstring>
#include <fstream>
#include <cmath>
#include <iomanip>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <map>
#include <deque>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <list>
#include <unordered_map>



using namespace std;

const int N = 10000;

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][j-1],c[i-1][j]);
            }
            maxl = max(maxl,c[i][j]);
        }
    }
    return maxl;
}

int main() {
    

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


}

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

using namespace std;

string s1, s2;

int lcs() {
  int i, j;
  int dp[s1.length()+1][s2.length()+1] = {};
  
  for(i = 1; i <= s1.length(); i++) {
    for(j = 1; j <= s2.length(); 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]);
    }
  
  }
  return dp[s1.length()][s2.length()];
}

int main(){
  int n;
  cin >> n;
  while(n--) {
    cin >> s1 >> s2;
    cout << lcs() << endl;
  }
  
  return 0;
}

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

#define MAX 1000

int dp[MAX+1][MAX+1];

int lcs(char x[], char y[]){
  for(int i = 0; i<=strlen(x); i++){
    dp[i][0] = 0;
    dp[0][i] = 0;
  }

  for(int i = 1; i<=strlen(x); i++){
    for(int j = 1; j<=strlen(y); j++){
      dp[i][j] = (x[i] == y[j]) ? dp[i-1][j-1] + 1 :
                                  max(dp[i-1][j],dp[i][j-1]);
    }
  }

  return dp[strlen(x)][strlen(y)];
}

int main(){

  int q;
  scanf("%d", &q);

  char X[MAX + 1];
  char Y[MAX + 1];
  for(int i=0; i<q; i++){
    scanf("%s\n%s\n", X, Y);
    printf("%d\n", lcs(X, Y));
  }

  return 0;
}

C++: #include <bits/stdc++.h>
#include <math.h>
#include <vector>
#include <queue>
#include <iomanip>
#include <string>
#include <algorithm>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define rep_1 (i,j,n) for(int i=j;i<n;i++)
typedef long long ll;
typedef long l;
const ll l_INF = 1010101010101010;
const int INF = 1010101010;
const int dx[] = {-1,0,1,0,-1,-1,1,1};
const int dy[] = {0,-1,0,1,1,-1,1,-1};

int main(){
  int q; cin>>q;
  rep(x,q){
    string s,t; cin>>s>>t;
    int dp[1010][1010];
    int n=s.size(),m=t.size();
    rep(i,n+1){
      rep(j,m+1){
        dp[i+1][j+1]=max(dp[i][j+1],dp[i+1][j]);
        if(s[i]==t[j])dp[i+1][j+1]=max(dp[i][j]+1,dp[i+1][j+1]);
      }
    }
    /*if(x==3){
      rep(i,n+1){
        rep(j,m+1){
          cout<<dp[i][j];
        }
        cout<<endl;
      }
    }*/
    cout<<dp[n][m]<<endl;
  }
}

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

string x;
string y;

int lcs(string x, string y){

  int c[1024][1024] = {{}};
  string nul = "0";
  x = nul + x;
  y = nul + y;


  /*
  for(int i = 0;i < x.size();i++) cout << " " << x[i];
  cout << endl;
  for(int i = 0;i < y.size();i++) cout << " " << y[i];
  cout << endl;
*/
  for(int i = 1;i < x.size();i++){
    for(int j = 1;j < y.size();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]);

/*
      for(int k = 1;k < x.size();k++){
        for(int l = 1;l < y.size();l++){
          cout << c[k][l] << ' ';
        }
        cout << endl;
      }
*/

    }
  }

  return c[x.size() - 1][y.size() - 1];
}



int main(){
  int q;
  cin >> q;

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