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;

constexpr 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;

   //c[i][j]のためにX[0],Y[0]に空白を挿入
   X=' '+X;
   Y=' '+Y;
   for(int i=1; i<m+1; i++) c[i][0]=0;
   for(int j=1; j<n+1; j++) c[0][j]=0;

   for(int i=1; i<m+1; i++){
      for(int j=1; j<n+1; 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 x, y;
   int n; cin >> n;
   for(int i=0; i<n; i++){
      cin >> x;
      cin >> y;
      cout << lcs(x, y) << endl;
   }

   return 0;
}

C++: #include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 150
#define L 1000

int LCSLength(char *X, char *Y){
  int m = strlen(X), n = strlen(Y);
  int i,j;
  int c[m+1][n+1];

  for(i=1; i<=m; i++) c[i][0] = 0;
  for(j=0; j<=n; j++) c[0][j] = 0;

  for(i=1; i<m+1; i++){
    for(j=1; j<n+1; j++){
      if(X[i-1] == Y[j-1]){
	c[i][j] = c[i-1][j-1] + 1;
      }
      else if(c[i-1][j] >= c[i][j-1]){
	c[i][j] = c[i-1][j];
      }
      else {
	c[i][j] = c[i][j-1];
      }
    }
  }

  return c[i-1][j-1];
}

int main(void){
  int q,i,j;
  int LCS[MAX];
  char X[MAX][L], Y[MAX][L];

  // input & calculate
  scanf("%d",&q);
  for(i=0; i<q; i++){
    scanf("%s", &X[i]);
    scanf("%s", &Y[i]);
    LCS[i] = LCSLength(X[i],Y[i]);
  }

  // output
  for(i=0; i<q; i++) printf("%d\n", LCS[i]);

  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repr(i, n) for (int i = (int)(n); i >= 0; i--)
#define REP(i, m, n) for (int i = (int)(m); i <= (int)(n); i++)
#define REPR(i, m, n) for (int i = (int)(m); i >= (int)(n); i--)
#define all(v) v.begin(), v.end()
typedef long long ll;
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; }

const long long INF = 1LL << 60;

int q;
int dp[1100][1100];

int main(){
  cin >> q;
  rep(k, q){
    string x, y;
    cin >> x >> y;
    int n = x.size();
    int m = y.size();

    memset(dp, 0, sizeof(dp));
    rep(i, n){
      rep(j, m){
        if(x[i] == y[j]) chmax(dp[i+1][j+1], dp[i][j]+1);
        else{
          chmax(dp[i+1][j+1], dp[i][j+1]);
          chmax(dp[i+1][j+1], dp[i+1][j]);
        }
      }
    }

    cout << dp[n][m] << endl;
  }

  return 0;
}

C++: #include <iostream>
#include <cmath>
#include <vector>

constexpr int MAX = 1000;
char ls[MAX];
char rs[MAX];
int table[MAX + 1][MAX + 1];


void calc_lcs() {
    scanf("%s", ls);
    scanf("%s", rs);
    int l_len = int(strlen(ls));
    int r_len = int(strlen(rs));
    for (int i = 0; i < l_len; i++) {
        table[i][0] = 0;
    }
    for (int i = 0; i < r_len; i++) {
        table[0][i] = 0;
    }

    for (int l_i = 1; l_i < l_len + 1; l_i++) {
        for (int r_i = 1; r_i < r_len + 1; r_i++) {
            if (ls[l_i - 1] == rs[r_i - 1]) {
                table[l_i][r_i] = table[l_i - 1][r_i - 1] + 1;
            } else {
                table[l_i][r_i] = std::max(table[l_i][r_i - 1], table[l_i - 1][r_i]);
            }
        }
    }
    std::cout << table[l_len][r_len] << std::endl;
}

int main() {
    int N;
    scanf("%d", &N);
    for (int i = 0; i < N; i++) {
        calc_lcs();
    }
}

C++: #include <bits/stdc++.h>
using namespace std;
#define r(i,n) for(auto i=0;i<n;i++)
#define s(c) static_cast<int>((c).size())

int dp[1002][1002];

int main(){
	int n;
	cin >> n;
	int x, y;
	string X, Y;
	r(k, n){
		cin >> X >> Y;
		x = X.size();
		y = Y.size();
		X = ' ' + X;
		Y = ' ' + Y;

		r(i, x+1)
			r(j, y+1)
				dp[i][j] = 0;

		for (int i = 1; i <= x; i++) {
			for (int j = 1; j <= y; 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]);
				}
			}
		}

		cout << dp[x][y] << endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll=long long;
using vin=vector<int>;
using vll=vector<long long>;
using vvin=vector<vector<int>>;
using vvll=vector<vector<long long>>;
using vstr=vector<string>;
using vvstr=vector<vector<string>>;
using vch=vector<char>;
using vvch=vector<vector<char>>;
using vbo=vector<bool>;
using vvbo=vector<vector<bool>>;
using vpii=vector<pair<int,int>>;
using pqsin=priority_queue<int,vector<int>,greater<int>>;
#define mp make_pair
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep2(i,s,n) for(int i=(s);i<(int)(n);i++)
#define all(v) v.begin(),v.end()
#define decp(n) cout<<fixed<<setprecision((int)n)
#define _GLIBCXX_DEBUG
int main(){
    int q;cin>>q;
    vstr x(q),y(q);
    rep(i,q)cin>>x[i]>>y[i];
    vin ans(q);
    rep(i,q){
        int sx=x[i].size();
        int sy=y[i].size();
        vvin dp(sx+1,vin(sy+1,0));
        rep(j,sx){
            rep(k,sy){
                if(x[i][j]==y[i][k])dp[j+1][k+1]=max(dp[j][k]+1,max(dp[j+1][k],dp[j][k+1]));
                else dp[j+1][k+1]=max(dp[j+1][k],dp[j][k+1]);
            }
        }
        ans[i]=dp[sx][sy];
    }
    rep(i,q)cout<<ans[i]<<endl;
}