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>                                            

using namespace std;                                         
                                                             
//L[i][j] X[0]..X[i]??¨X[0]..Y[j]???LCS                        
int L[1001][1001]={};                                        
int main(){
  int testnum;
  cin>>testnum;                                              
  for(int t=0;t<testnum;++t){                                
    string X,Y;                                              
    cin>>X>>Y;
    
    for(int i=1;i<=X.length();++i){                          
      for(int j=1;j<=Y.length();++j){                        
        if(X[i-1]==Y[j-1])
          L[i][j] = 1 + L[i-1][j-1];                         
        else
          L[i][j] = max(L[i][j-1],L[i-1][j]);
      }
    }

    cout << L[X.length()][Y.length()] << endl;
  }
 
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <string>
using namespace std;
int dp[1005][1005] = { 0 };
int main() {
	int n;
	cin >> n;
	for (int i = 0; i < n; i++) {
		string x, y;
		cin >> x >> y;
		for (int j = 0; j < 1005; j++)
			for (int k = 0; k < 1005; k++) dp[j][k] = 0;
		for (int j = 1; j <= x.size(); j++) {
			for (int k = 1; k <= y.size(); k++) {
				dp[j][k] = max(dp[j][k - 1], dp[j - 1][k]);
				if (x[j - 1] == y[k - 1]) {
					dp[j][k] = max(dp[j][k], dp[j - 1][k - 1] + 1);
				}
			}
		}
		cout << dp[x.size()][y.size()] << endl;
	}
	return 0;
}

C++: #define _GLIBCXX_DEBUG
typedef long long ll;
#include <bits/stdc++.h>

using namespace std;

ll mod = 1000000007;

template<class Type> inline bool chmax(Type& a, Type b) { if (a < b) { a = b; return 1; } return 0; }
template<class Type> inline bool chmin(Type& a, Type b) { if (a > b) { a = b; return 1; } return 0; }

template<class Type>
Type modpow(Type a, Type n, Type mod)
{
	Type res = 1;
	while (0 < n)
	{
		if (n & 1)
		{
			res = res * a % mod;
		}
		a = a * a % mod;
		n >>= 1;
	}
	return res;
}

template<class Type>
Type gcd(Type x, Type y)
{
	Type r;
	if (x < y)
	{
		swap(x, y);
	}

	while (0 < y)
	{
		r = x % y;
		x = y;
		y = r;
	}
	return x;
}

template<class Type>
bool isPrime(Type x)
{
	if (x == 2) return true;
	if (x < 2 || x % 2 == 0) return false;

	for (Type i = 3; i <= sqrt(x); i += 2)
	{
		if (x % i == 0) return false;
	}
	return true;
}

template<class Type>
vector<bool> eratos(Type n)
{
	vector<bool> isPrime(n + 1, true);
	isPrime[0] = isPrime[1] = false;
	for (Type i = 2; i <= n; i++)
	{
		if (isPrime[i])
		{
			Type j = i + i;
			while (j <= n)
			{
				isPrime[j] = false;
				j = j + i;
			}
		}
	}
	return isPrime;
}

bool binarySearchJudge(vector<int> a, int index, int key)
{
	if (key <= a[index]) return true;
	else return false;
}

int binarySearch(vector<int> a, int key)
{
	int ng = -1;
	int ok = a.size();
	while (1 < abs(ng - ok))
	{
		int mid = (ng + ok) / 2;
		if (binarySearchJudge(a, mid, key)) ok = mid;
		else ng = mid;
	}
	return a[ok] == key;
}

int lcs(string x, string y)
{
	int m = x.size();
	int n = y.size();
	vector<vector<int>> dp(m, vector<int>(n));

	dp[0][0] = (x[0] == y[0]) ? 1 : 0;
	for (int i = 1; i < m; i++)
	{
		if (y[0] == x[i]) dp[i][0] = 1;
		else dp[i][0] = max(dp[i - 1][0], 0);
	}
	for (int i = 1; i < n; i++)
	{
		if (x[0] == y[i]) dp[0][i] = 1;
		else dp[0][i] = max(dp[0][i - 1], 0);
	}

	for (int i = 1; i < m; i++)
	{
		for (int j = 1; j < n; 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]);
		}
	}
	return dp[m - 1][n - 1];
}

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

C++: #include <iostream>
#include <string>
#include <map>
#include <set>
#include <algorithm>
using namespace std;
#define MAX 100000

static const int N =100;

int lcs(string X,string Y){
  int c[N+1][N+1];
  int m=X.size();
  int n=Y.size();
  int ans=0;
  X= ' '+X;
  Y= ' '+Y;
  for(int i;i<=m;i++)c[i][0]=0;
  for(int j;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]);
      }
      ans=max(ans,c[i][j]);
    }
  
  }
  return ans;
}

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

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

#define MAX 1000

int lcs(string x, string y) {
  int c[MAX + 1][MAX + 1];
  int m = x.size();
  int n = y.size();
  int maxl = 0;
  x = ' ' + x;
  y = ' ' + y;
  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 q;
  cin >> q;

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

  return 0;
}