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 <algorithm>
using namespace std;

int lcs( string X , string Y) {
int c[ N + 1 ][ N + 1 ] ; 
int m = X.size() ; 
int n = Y.size() ; 
int max1 = 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]);
       }
       max1 = max(max1, c[i][j] ) ;
     }
   }
 return max1 ;
}

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>
using namespace std;
static const int MAX = 1001;
 
void lcs(string X, string Y) {
    int dp[MAX][MAX];  
    int i,j;
 
    int xLength = X.size();
    int yLength = Y.size();
 
 
    // initialize dp[][]
    for (i = 1; i <= xLength; i++)
        dp[i][0] = 0;
    for (i = 1; i <= yLength; i++)
        dp[0][i] = 0;
 
    for (i = 1; i <= xLength; i++){
        for (j = 1; j <= yLength; j++){
            // Because the original string is 0-based , so subtracted from 1
            if (X[i - 1] == Y[j - 1]) {
                dp[i][j] = dp[i-1][j-1] + 1;
            }else {
                dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
            }
        }
    }
 
    // testing code: print out the dp[][]
    // cout << "j";
    // for (j = 1; j <= yLength; j++)
    //  cout << ' ' << j ;
    // cout << endl;
         
 
    // for (i = 1; i <= xLength; i++){
    //  cout << i << '.';
    //  for (j = 1; j <= yLength; j++){
    //      cout << dp[i][j] << ' ';
    //  }
    //  cout << endl;
    // }
 
    cout << dp[xLength][yLength] << endl;
}
 
int main() {
    int n , i;
    string X, Y;
 
    cin >> n;
    for (i = 0 ; i < n; i++ ) {
        cin >> X;
        cin >> Y;
        lcs(X, Y);
    }
 
    return 0;
 
}

C++: #include<iostream>
#include<string>
#include<algoritm>
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 n;
  cin>>n;
  for(int i = 0; i<n;i++){
    cin>>s1>>s2;
    cout<<lcs(s1,s2)<<endl;
  }
  return 0;
}

C++: //
#if 0

#endif // 0
#include<iostream>
#define MAX 1010
using namespace std;
int l[MAX][MAX];

int main()
{
    int num;
    cin>>num;       // int l[MAX][MAX];

    for(int i=0;i<num;i++)
    {
        string s1,s2;
        cin>>s1>>s2;
        //int l[MAX][MAX];
        for(int m=0;m<=s1.size();m++)
            for(int n=0;n<=s2.size();n++)
            {
                if(m<=0||n<=0)
                    l[m][n]=0;
                else if(s1[m-1]==s2[n-1])
                    l[m][n]=l[m-1][n-1]+1;
                else
                    l[m][n]=max(l[m][n-1],l[m-1][n]);
            }
        cout<<l[s1.size()][s2.size()]<<endl;
    }
    return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#include<map>
#include<set>
#include<string>
#include<queue>
#include<stack>
using namespace std;
#define INF (1 << 30) - 1
#define LINF 1LL << 60
const int MOD = 1000000007;
using ll = long long;
using P = pair<int, int>;

int dp[1010][1010];

int main(){
  int q;
  cin >> q;
  for(int i = 0; i < q; ++i){
    string x, y;
    cin >> x >> y;
    fill((int*)dp, (int*)dp + sizeof(dp) / sizeof(int), 0);
    // fill((int*)dp, (int*)(dp + 1010), 0);

    int xs = x.size();
    int ys = y.size();

    for(int i = 0; i < xs; ++i){
      for(int j = 0; j < ys; ++j){
        if(x[i] == y[j])dp[i + 1][j + 1] = dp[i][j] + 1;
        else dp[i + 1][j + 1] = max(dp[i + 1][j], dp[i][j + 1]);
      }
    }

    cout << dp[xs][ys] << endl;
  }

  return 0;
}

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

std::string x,y;
int lcs[1000][1000] = {0};

int max(int k,int l){
  if(k>l){
    return k;
  }else{
    return l;
  }
}

void LCS(int i,int j){
  if(x[i] == y[j]){
    lcs[i][j] = lcs[i-1][j-1]+1;
  }else{
    lcs[i][j] = max(lcs[i-1][j],lcs[i][j-1]);
  }
}

void pre(){
  for(int i=0;i<(int)y.size();i++){
    if(x[0] == y[i]){
      lcs[0][i] = 1;
    }else{
      lcs[0][i] = 0;
    }
  }
  for(int i=0;i<(int)x.size();i++){
    if(x[i] == y[0]){
      lcs[i][0] = 1;
    }else{
      lcs[i][0] = 0;
    }
  }
}

int main(){
  int q;
  std::cin >> q;
  for(int k=0;k<q;k++){
    std::cin >> x;
    std::cin >> y;
    int size_x=x.size(),size_y=y.size();
    pre();
    for(int i=1;i<size_x;i++){
      for(int j=1;j<size_y;j++){
	LCS(i,j);
      }
    }

    /*for(int i=0;i<size_x;i++){
      for(int j=0;j<size_y;j++){
	std::cout << lcs[i][j] << ' ';
      }
      std::cout << '\n';
    }
    */
    std::cout << lcs[size_x-1][size_y-1] << '\n'; 

  }
  return 0;
}