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++: #pragma region template
#include "bits/stdc++.h"
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
const long long MOD = 1e9 + 7, MAX = 1e18, larg = 1e5, INF = -1e9;
long long A, B, C, D, E, F, G, H, I, J, K, L, N, M, O, P, Q, R, S, T, U, V, W, x, y, z;
long long max_value = INF, max_index = -1;
long long min_value = MAX, min_index = -1;
typedef long long ll;
typedef pair<ll, ll> Pa;

ll dp[1001][1001];
ll ans[150];
int main() {
	cin >> N;
	rep(n, N){
		string X, Y;
		cin >> X;
		cin >> Y;
		rep(i, 1001){
			rep(j, 1001){
				dp[i][j] = 0;
			}
		}
		ll maxv = 0;
		rep(i, X.size()){
			rep(j, Y.size()){
				if(X[i] == Y[j]) dp[i+1][j+1] = max(dp[i+1][j+1], dp[i][j]+1);
				dp[i+1][j] = max(dp[i+1][j], dp[i][j]);
				dp[i][j+1] = max(dp[i][j+1], dp[i][j]); 
			}
		}
		rep(i, X.size()+1){
			rep(j, Y.size()+1){
				maxv = max(maxv, dp[i][j]);
			}
		}
		ans[n] = maxv;
	}
	rep(i, N){
		cout << ans[i] << endl;
	}
}

C++: #include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
typedef long long ll;
typedef pair<int,int> pp;
const int INF = 1e9;
const int MOD = 1000000007;


int main(){
        int q;
        cin >>q;
        rep(i,q){
                string x,y;
                cin >> x >>y;
                vector<vector<int>> dp(x.size()+1,vector<int>(y.size()+1,0));
                
                for(int i=1;i<=x.size();i++){
                        for(int j=1;j<=y.size();j++){
                                if(x.at(i-1) == y.at(j-1)) dp.at(i).at(j) = dp.at(i-1).at(j-1) + 1;
                                else dp.at(i).at(j) = max(dp.at(i-1).at(j),dp.at(i).at(j-1));
                        }
                }
                
                cout << dp.at(x.size()).at(y.size()) << endl;
        }

        return 0;
}

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; // X[0] に空白を挿入
    Y = ' ' + Y; // Y[0] に空白を挿入
     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]);
                                            }
                                        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;
                                                }

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

int lcs(string str1, string str2) {
	int n1 = str1.size();
	int n2 = str2.size();
	int A[n1 + 1][n2 + 1];
	for (int i = 0; i <= n1; i++) A[i][0] = 0;
	for (int j = 1; j <= n1; j++) A[0][j] = 0;

	for (int i = 1; i <= n1; i++) {
		for (int j = 1; j <= n2; j++) { 
			if (str1[i - 1] == str2[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[n1][n2];
}

int main() {
	int n;
	string str1, str2;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> str1 >> str2;
		cout << lcs(str1, str2) << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
using namespace std;
  
static const int N = 1000;
  
int las(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 = 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]);
}
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;
}