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;

#define ll long long
#define vvi vector<vector<int>>
#define vec vector
#define pq priority_queue
#define all(v) (v).begin(), (v).end()
#define uniqueV(x) sort(x.begin(), x.end()); x.erase(unique(x.begin(), x.end()), x.end());
#define rep(i, n) for (int (i) = (0); (i) < (n); ++(i))
#define repp(i, m, n) for (int (i) = (m); (i) < (n); ++(i))
#define dbg(x) cerr << #x << ": " << x << endl;
#define dbg2(x, y) cerr<<"("<<#x<<", "<<#y<<") = "<<"("<<x<<", "<<y<<")"<<endl;
#define dbg3(x, y, z) cerr<<"("<<#x<<", "<<#y<<", "<<#z<<") = "<<"("<<x<<", "<<y<<", "<<z<<")"<<endl;
#define dbgB(value, size) cerr<<#value<<": "<<bitset<size>(value) << endl;
#define line() cerr << "---------------" << endl;

const int dx[] = {1, -1, 0, 0};
const int dy[] = {0, 0, -1, 1};
const double PI = 3.14159265358979323846;

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

template<typename T>
void printA(vector<T> &printArray, char between = ' ') {
   int paSize = printArray.size();
   for (int i = 0; i < paSize; i++) { cerr << printArray[i] << between;}
   if (between != '\n') {cerr << endl;}
}

// ------------------------------------------------------------------------------------------

int q;
string x, y;
int dp[1111][1111];

void solve() {
   for (int i = 1; i <= x.size(); i++) {
      for (int j = 1; j <= y.size(); 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.size()][y.size()] << endl;
}

int main() {
   cin >> q;
   while (q--) {
      fill(dp[0], dp[1111], 0);
      cin >> x >> y;
      solve();
   }

   return 0;
}

C++: #include<iostream>
#include<vector>b
using namespace std;
int main()
{
	int kurikaeshi;
	vector<int> answer;
	cin >> kurikaeshi;
	for (int variable = 0;variable < kurikaeshi;++variable) {
		char X[1024], Y[1024];
		int LX = 0, LY = 0;
		vector<vector<int>> L;
		cin >> X >> Y;
		for (int i = 0;X[i] != 0;++i) LX += 1;
		for (int j = 0;Y[j] != 0;++j) LY += 1;
		L.resize(LX+1);
		for (int k = 0;k < LX + 1;++k) L[k].resize(LY+1);
		for (int i = 0;X[i] != 0;++i) {
			for (int j = 0;Y[j] != 0;++j) {
				if (i == 0 || j == 0) {
					L[i][j] = 0;
				}
				else if (X[i] == Y[j]) {
					L[i+1][j+1] = L[i+1][j] + 1;
				}
				else {
					L[i+1][j+1] = L[i][j+1] > L[i+1][j] ? L[i][j+1] : L[i+1][j];
				}
			}
		}
		answer.push_back(L[LX][LY]+1);
	}
	for (int variable = 0;variable < kurikaeshi;++variable) {
		cout << answer[variable] << endl;
	}
}

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

using namespace std;

int results[1001][1001];

int lcs(string x, string y)
{
    // initialize
    for (int i = 0; i < 1001; ++i) {
        for (int j = 0; j < 1001; ++j)
            results[i][j] = 0;
    }

    int maxlcs = 0;
    for (int i = 1; i <= x.length(); ++i) {
        for (int j = 1; j <= y.length(); ++j) {
            if (x[i-1] == y[j-1])
                results[i][j] = results[i-1][j-1] + 1;
            else
                results[i][j] = max(results[i-1][j], results[i][j-1]);

            if (maxlcs < results[i][j])
                maxlcs = results[i][j];
        }
    }
    return maxlcs;
}

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

    vector<string> x(n);
    vector<string> y(n);
    for (int i = 0; i < n; ++i)
        cin >> x[i] >> y[i];

    for (int i = 0; i < n; ++i)
        cout << lcs(x[i], y[i]) << '\n';
}

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

int main() {
    int q;
    cin >> q;
    
    rep(i,q) {
        string X,Y;
        cin >> X >> Y;
        int lX=X.size(), lY=Y.size();
        vector<vector<int>> dp(lX+1, vector<int>(lY+1,0));

        rep(i,lX)
            rep(j,lY)
                if(X.at(i) == Y.at(j))
                    dp.at(i+1).at(j+1) = dp.at(i).at(j)+1;
                else
                    dp.at(i+1).at(j+1) = max(dp.at(i+1).at(j), dp.at(i).at(j+1));

        cout << dp.at(lX).at(lY) << 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];
    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-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;
}