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 <stdio.h>

int t[1001][1001];
 
int main(){
  char X[1000],Y[1000];
  int i, j, n, x, y, k;
 
  scanf("%d",&n);
 
  for(k=0; k<n; k++){
    scanf("%s%s",X+1,Y+1);
    x=strlen(X+1);
    y=strlen(Y+1);
 
    for(i=1; i<=x; i++)
      for(j=0; j<=y;j++)
    t[i][j]=0;
 
    for(i=1;i<=x;i++){
      for(j=1;j<=y;j++){
    if(X[i] == Y[j])  t[i][j]=t[i-1][j-1]+1;
    else if(t[i-1][j]>=t[i][j-1]) t[i][j]=t[i-1][j];
    else t[i][j]=t[i][j-1];
      }
    }
    printf("%d\n", t[i-1][j-1]);
  }
  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 n; 

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

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i=0; i < (int)(n); i++)
using ull = unsigned long long;
using ll = long long;

int dp[1010][1010];

void LCS(string X, string Y) {
    rep(i, X.size()+1) rep(j, Y.size()+1) dp[i][j] = 0;

    rep(i, X.size()) rep(j, Y.size()) {
        if (X[i] == Y[j]) dp[i+1][j+1] = max({dp[i][j]+1, dp[i][j+1], dp[i+1][j]});
        else dp[i+1][j+1] = max({dp[i][j], dp[i][j+1], dp[i+1][j]});
    }

    cout << dp[X.size()][Y.size()] << endl;
}


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

    rep(i, q) {
        string x, y;
        cin >> x >> y;

        LCS(x, y);
    }

    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 i,j;
  int maxl=0;
  X=' '+X;
  Y=' '+Y;
 
  for(i=1;i<=m;i++) c[i][0]=0;
  for(j=1;j<=n;j++) c[0]c[j]=0;

  for(i=1;i<=m;i++){
    for(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)<<enl;
  }
  return 0;
}

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

int main(void){
	int q;
	string a,b;
	cin>>q;
	while(q--){
		cin>>a>>b;
		int dp[1010][1010] = {0};
		for(int j = 0 ; j < a.size() ; j ++){
			for(int i = 0 ; i < b.size() ; i ++){
				if(a[j] == b[i]){
					dp[j+1][i+1] = dp[j][i]+ 1;
				}else{
					dp[j+1][i+1] = max(dp[j][i+1],dp[j+1][i]);
				}
			}
		}
		cout<<dp[a.size()][b.size()]<<endl;
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
#define repd(i,a,b) for (int i=(a);i<(b);i++)
#define rep(i,n) repd(i,0,n)
#define all(x) (x).begin(),(x).end()
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
typedef long long ll;
const long long INF = 1LL << 60;
typedef pair<int, int> P;
int dp[1001][1001];
int main()
{
    int q;
    cin >> q;
    rep(i, q) {
        string A, B;
        cin >> A >> B;
        rep(i, A.size()) {
            rep(j, B.size()) {
                dp[i + 1][j + 1] = max(dp[i + 1][j], dp[i][j + 1]);
                if (A[i] == B[j]) chmax(dp[i + 1][j + 1], dp[i][j] + 1);
            }
        }
        cout << dp[(int)A.size()][(int)B.size()] << endl;
    }
    return 0;
}

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

using namespace std;

int lcs(string a, string b)
{
	vector<vector<int> > dp(1001, vector<int>(1001));
	for (int i = 0; i < a.size(); ++i)
	{
		for (int j = 0; j < b.size(); ++j)
		{
			if (a[i] == b[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]);
			}
		}
	}
	return(dp[a.size()][b.size()]);
}

void solve()
{
	int q;
	cin >> q;
	for (int i = 0; i < q; ++i)
	{
		string a, b;
		cin >> a >> b;
		cout << lcs(a, b) << endl;
	}
}

int main()
{
	solve();
	return(0);
}

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

using namespace std;

int LCS(string X, string Y) {

	int lcs[X.size() + 1][Y.size() + 1];

	for (int i = 0; i < X.size(); ++i) {
		lcs[0][i] = 0;
	}
	for (int i = 0; i < Y.size(); ++i) {
		lcs[i][0] = 0;
	}

	for (int i = 1; i <= X.size(); ++i) {
		for (int j = 1; j <= Y.size(); ++j) {
			if (X[i - 1] == Y[j - 1]) {
				lcs[i][j] = lcs[i - 1][j - 1] + 1;
			} else if (lcs[i - 1][j] > lcs[i][j - 1]) {
				lcs[i][j] = lcs[i - 1][j];
			} else {
				lcs[i][j] = lcs[i][j - 1];
			}
		}
	}

	return lcs[X.size()][Y.size()];
}

int main() {

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

	for (int i = 0; i < q; ++i) {
		string X, Y;
		cin >> X >> Y;
		cout << LCS(X, Y) << endl;
	}

	return 0;

}