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 <vector>
#include <algorithm>
using namespace std;


long long calc(int i, int j, vector<vector<long long> > &l, const string& x, const string& y){
  if(i == 0 || j == 0){
    l[i][j] = 0;
    return l[i][j];
  }
  if(l[i][j] >= 0){
    return l[i][j];
  }else{
    if(x[i-1] == y[j-1]){
      l[i][j] = 1 + calc(i-1, j-1, l, x, y);
    }else{
      l[i][j] = max(calc(i-1, j, l, x, y), calc(i, j-1, l, x, y));
    }
    return l[i][j];
  }
}
int main(){
  int n;
  cin >> n;
  for(int i = 0; i < n; i++){
    string x,y;
    cin >> x >> y;
    vector<vector<long long> > l(x.length()+1, vector<long long>(y.length()+1, -1));
    cout << calc(x.length(), y.length(), l, x, y) << endl;
  }
}

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

int lcs(string s, string t){
        int a[s.size()+1][t.size()+1];
        for(int i=0;i<s.size()+1;i++) a[i][0]=0;
        for(int i=0;i<t.size()+1;i++) a[0][i]=0;
        for(int i=1;i<s.size()+1;i++){
                for(int j=1;j<t.size()+1;j++){
                        if(s[i-1]==t[j-1]) a[i][j] = a[i-1][j-1]+1;
                        else a[i][j] = max(a[i-1][j], a[i][j-1]);
                }
        }
        return a[s.size()][t.size()];
}

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

C++: // 5/5
// 2-3-2. 最長共通部分裂問題の類題

#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int, int>;
using Graph = vector<vector<int>>;

int dp[1010][1010];

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

    int n, m;
    // cin >> n >> m;

    vector<int> ans;

    rep(p, q) {
        string s, t;
        cin >> s >> t;

        n = s.size();
        m = t.size();
        memset(dp, 0, sizeof(dp));

        dp[0][0] = 0;

        rep(i, n) {
            rep(j, m) {
                if (s[i] == t[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[n][m] << endl;
        ans.push_back(dp[n][m]);
    }

    for (auto v : ans) cout << v << endl;
}

C++: #include <algorithm>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <limits>
#include <map>
#include <queue>
#include <set>
#include <tuple>
#include <vector>

using namespace std;

#define rep(i, n) for (int64_t i = 0; i < (n); i++)
#define irep(i, n) for (int64_t i = 0; i <= (n); i++)
#define rrep(i, n) for (int64_t i = (n)-1; i >= 0; i--)
#define rirep(i, n) for (int64_t i = n; i >= 0; i--)

int dp[1'001][1'001];

void solve(const string& x, const string& y)
{
    irep(i, x.size()) irep(j, y.size())
    {
        if (i == 0 || j == 0) {
            dp[i][j] = 0;
        } else {
            dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]);
            if (x[i - 1] == y[j - 1]) {
                dp[i][j] = max(dp[i][j], dp[i - 1][j - 1] + 1);
            }
        }
    }
    cout << dp[x.size()][y.size()] << endl;
}

int main()
{
    int n;
    cin >> n;
    rep(i, n)
    {
        string x, y;
        cin >> x >> y;
        solve(x, y);
    }
    return 0;
}