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 <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef long int li;
typedef long double lb;
#define rep(i,j,n) for (ll i = j; i < (n); i++)
#define repr(i,j,n) for(ll i = j; i >= (n); i--)
#define all(x) (x).begin(),(x).end()
#define CLR(mat,f) memset(mat, f, sizeof(mat))
#define IN(a, b, x) (a<=x&&x<b)
#define out(ans) cout << ans << endl
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
typedef pair<ll,ll>P;
const ll mod=1e9+7;
const ll INF = 1LL<<60;
const ll m=1LL<<32;

const ll MAX_N=1001;

ll lcs(string a,string b){

  ll c[MAX_N][MAX_N];
  ll as=a.size();
  ll bs=b.size();
  a.insert(0," ");
  b.insert(0," ");

  CLR(c,0);
  rep(i,1,as+1){
    rep(j,1,bs+1){
      if(a[i]==b[j])c[i][j]=c[i-1][j-1]+1;
      else chmax(c[i][j],max(c[i-1][j],c[i][j-1]));
    }
  }

  return c[as][bs];
}

int main(){

  ll n;cin>>n;

  while(n--){
    string a,b;cin>>a>>b;
    out(lcs(a,b));
  }

  return 0;
}

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

int Longest(string x, string y) {
  int L[1001][1001];
  int maxl = -1;
  int xlen = x.size();
  int ylen = y.size();

  x = ' ' + x;
  y = ' ' + y;

  for (int i = 1; i <= xlen; i++) L[i][0] = 0;
  for (int j = 1; j <= ylen; j++) L[0][j] = 0;

  for (int i = 1; i <= xlen; i++) {
    for (int j = 1; j <= ylen; j++) {
      if (x[i] == y[j])
        L[i][j] = L[i-1][j-1] + 1;
      else
        L[i][j] = max(L[i][j-1], L[i-1][j]);

      maxl = max(maxl, L[i][j]);
    }
  }

  return maxl;
}

int main() {
  string X, Y;
  int n;
  int result[10000];

  cin >> n;

  for (int i = 0; i < n; i++) {
    cin >> X;
    cin >> Y;
    result[i] =  Longest(X, Y);
    cout << result[i] << endl;
  }

  return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
#include <cstring>
using namespace std;
typedef long long ll;
typedef long long ll;
ll q, dp[1010][1010];
string s, t;
int main(void){
    // Your code here!
    cin >> q;
    for (ll k = 0; k < q; k++) {
        cin >> s >> t;
        for (ll i = 1; i <= s.length(); i++) {
            for (ll j = 1; j <= t.length(); j++) {
                dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]);
                if (s[i - 1] == t[j - 1]) {
                    dp[i][j] = max(dp[i][j], dp[i - 1][j - 1] + 1);
                }
            }
        }
        cout << dp[s.length()][t.length()] << endl;
    }
}

C++: #include <iostream>
#include <vector>
#include <map>
#include <algorithm>
#include <queue>
#include <string>
#define REP(i,a,b) for (int i = a; i < (b); i++)
#define sz(t) int(t.size())
#define INF 1000000000
const int DIV = 1000000000 + 7;
using namespace std;
typedef long long ll;

int solve(string x, string y) {
    int dp[1050][10050];
    x = ' ' + x;
    y = ' ' + y;
    int lx = x.size();
    int ly = y.size();
    REP(i, 0, lx) dp[0][i] = 0;
    REP(i, 0, ly) dp[i][0] = 0;
    int ans = 0;
    REP(i, 1, ly) {
        REP(j ,1, lx) {
            if (y[i] == x[j]) {
                dp[i][j] = dp[i - 1][j - 1] + 1;
            } else {
                dp[i][j] = max(dp[i][j - 1], dp[i - 1][j]);
            }  
            ans = max(ans, dp[i][j]);
        }
    }

    return ans;
}

int main(void) {
    int n;
    cin >> n;

    REP(i, 0, n) {
        string x, y;
        cin >> x;
        cin >> y;
        cout << solve(x, y) << endl;
    }
}

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

int Longest(string x, string y) {
  int L[1001][1001];
  int maxl = -1;
  int xlen = x.size();
  int ylen = y.size();

  x = ' ' + x;
  y = ' ' + y;

  for (int i = 1; i <= xlen; i++) L[i][0] = 0;
  for (int j = 1; j <= ylen; j++) L[0][j] = 0;

  for (int i = 1; i <= xlen; i++) {
    for (int j = 1; j <= ylen; j++) {
      if (x[i] == y[j]) {
        L[i][j] = L[i-1][j-1] + 1;
      } else {
        L[i][j] = max(L[i][j-1], L[i-1][j]);
        }
      maxl = max(maxl, L[i][j]);
    }
  }

  return maxl;
}

int main() {
  string X, Y;
  int n;
  cin >> n;

  for (int i = 0; i < n; i++) {
    cin >> X;
    cin >> Y;
    cout << Longest(X, Y) << endl;
  }

  


  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n,x) for(int i=n;i<x;i++)
const int MAX_N = 1000;

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

    int dp[MAX_N+1][MAX_N+1];

    while(q > 0){
        string x, y; cin >> x >> y;

        int X = x.size(), Y = y.size();
        rep(i, 0, X){
            rep(j, 0, Y){
                if(x[i] == y[j]) dp[i+1][j+1] = dp[i][j] + 1;
                else dp[i+1][j+1] = max(dp[i][j+1], dp[i+1][j]);
            }
        }

        cout << dp[X][Y] << endl;

        q--;
    }

    return 0;
}