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<cmath>
#include<algorithm>
#include<string>
#include<vector>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<iomanip>
#include<bitset>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> P;
typedef pair<ll,P> P1;
typedef pair<P,P> P2;
#define pu push
#define pb push_back
#define mp make_pair
#define eps 1e-7
#define INF 1000000000
#define fi first
#define sc second
#define rep(i,x) for(ll i=0;i<x;i++)
#define repn(i,x) for(ll i=1;i<=x;i++)
#define SORT(x) sort(x.begin(),x.end())
#define ERASE(x) x.erase(unique(x.begin(),x.end()),x.end())
#define POSL(x,v) (lower_bound(x.begin(),x.end(),v)-x.begin())
#define POSU(x,v) (upper_bound(x.begin(),x.end(),v)-x.begin())

const int MAX = 510000;
const int MOD = 1000000007;

int main(){
  ll N; cin >> N;
  vector<string> v(2 * N);
  rep(i, 2 * N) cin >> v[i];
  rep(loop, N){
    string s,t;
    s = v[2 * loop]; t = v[2 * loop + 1];
    ll a = s.size(), b = t.size();
    vector<vector<ll> > dp(a + 1 , vector<ll>(b + 1, 0) );
    rep(i,a){
      rep(j,b){
        if(s[i] == t[j]){
          dp[i + 1][j + 1] = max(dp[i + 1][j] , max(dp[i][j + 1], dp[i][j] + 1) );
        }
        else{
          dp[i + 1][j + 1] = max(dp[i + 1][j] , dp[i][j + 1]);
        }
      }
    }
    /*
    rep(i,a + 1){
      rep(j,b + 1){
        cout << dp[i][j] << " ";
      }
      cout << endl;
    }
    */
    cout << dp[a][b] << endl;
  }
}

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], LMAX=0;;
  int m=X.size(), n=Y.size();

  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]);
      }
      LMAX=max(LMAX, c[i][j]);
    }
  }

  return LMAX;
}

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 <algorithm>
using namespace std;
#define MAX 1000

int c[MAX + 1][MAX + 1];

int lcs(string x, string y) {
	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][j - 1], c[i - 1][j]);
			}
			maxl = max(maxl, c[i][j]);
		}
	}
	return maxl;
}

int main()
{
	int q;
	cin >> q;
	string x, y;
	int l[150] = { 0 };

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

C++: #include<bits/stdc++.h>

using namespace std;

void printdpTable(vector<vector<int> > a){
    cout << "- dp table -" << endl;
    for(int i = 0; i < a.size(); i++){
        for(int j = 0; j < a[0].size(); j++){
            cout << a[i][j] << " ";
        }
        cout << endl;
    }
    cout << "- dp table -" << endl;
}

//すべての最長部分文字列をの長さ出力する
void printLcs(string x, string y){
    int n = x.length();
    int m = y.length();
    vector<vector<int> > a(n+1, vector<int>(m+1, 0));
    x = ' ' + x;
    y = ' ' + y;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= m; j++){
            if(x[i] == y[j]){
                a[i][j] = a[i-1][j-1]+1;
            }else{
                a[i][j] = max(a[i-1][j], a[i][j-1]);
            }
        }
    }
    cout << a[n][m] << endl;
}

int main(void){
    int n;
    cin >> n;
    string x, y;
    for(int i = 0; i < n; i++){
        cin >> x >> y;
        printLcs(x,y);
    }
    return 0;
}

C++: #include "iostream"
#include "string.h"

using namespace std;

int L[1001][1001];

int lcs( char s1[], char s2[], int l1, int l2 ) {

	if (L[l1][l2] != 0)return L[l1][l2];

	if (l1 == 0 || l2 == 0) return 0;
	else if (s1[l1-1] == s2[l2-1]) L[l1][l2] = lcs(s1, s2, l1 - 1, l2 - 1) + 1;
	else {
		int lsc1 = lcs(s1, s2, l1 - 1, l2);
		int lsc2 = lcs(s1, s2, l1, l2 - 1);

		if (lsc1 > lsc2) L[l1][l2] = lsc1;
		else L[l1][l2] = lsc2;
	}

	return L[l1][l2];
}

int main() {

	int n;
	char s1[1000], s2[1000];

	cin >> n;

	for (int i = 0; i < n; i++) {
		cin >> s1;
		cin >> s2;

		cout << lcs(s1, s2, strlen(s1), strlen(s2)) << endl;
	}

	return 0;
}