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<stdio.h>
#include<string.h>
#define MAX 1001
??
int LCSLength(char [], char []);
??
int main()
{
????int i, q, Z[MAX];
????char X[MAX], Y[MAX];
??
????scanf("%d", &q);
????for(i=0; i<q; i++)
????????{
????????????scanf("%s", X);
????????????scanf("%s", Y);
????????????Z[i] = LCSLength(X, Y);
????????}
??
????for(i=0; i<q; i++)
????????{
????????????printf("%d\n", Z[i]);
????????}
????
????return 0;
}
??
int LCSLength(char X[], char Y[])
{
????int i, j, c[MAX][MAX];
????int m = strlen(X);
????int n = strlen(Y);
??
????for(i=1; i<=m; i++) c[i][0] = 0;
????for(j=0; j<=n; j++) c[0][j] = 0;
??
????for(i=1; i<=m; i++)
????????{
????????????for(j=1; j<=n; j++)
????????{
????????????if(X[i-1] == Y[j-1]) c[i][j] = c[i-1][j-1] + 1;
????????????else if(c[i-1][j-1] >= c[i][j-1]) c[i][j] = c[i-1][j];
????????????else c[i][j] = c[i][j-1];
????????}
????????}
??????
????return c[m][n];
}

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

using namespace std;

string  X,Y;
int q;

int do_dp(int ax,int ay){
  int dp[ax + 100][ay + 100] = {0};
  
  for(int i = 0;i < ax;i++){
    if(X[i] == Y[0]) dp[i][0] = 1;
    if(i > 0) dp[i][0] = max(dp[i][0],dp[i - 1][0]);
  }
  
  for(int j = 0;j < ay;j++){
    if(X[0] == Y[j]) dp[0][j] = 1;
    if(j > 0) dp[0][j] = max(dp[0][j],dp[0][j - 1]);
  }

  for(int i = 1;i < ax;i++){
    for(int j = 1;j < ay;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]);
      }
    }
  }
  
  for(int i = 0;i < ax;i++){
    for(int j = 0;j < ay;j++){
      cout << dp[i][j] << " ";
    }
    cout << '\n';
  }
  
  return dp[ax - 1][ay - 1];
}

int main(){
  string str;
  
  cin >> q;
  
  int A[q];
  
  for(int i = 0;i < q;i++){
    cin >> X;
    cin >> Y;
    //cout << X.size() << " " << Y.size() << '\n';
    A[i] = do_dp(X.size(),Y.size());
  }
  
  for(int i = 0;i < q;i++){
    cout << A[i] << '\n';
  }
  
  return 0;
}

C++: #include <iostream>
#include <string>
#define int long long
//#define _DEBUG
using namespace std;
string sa, sb;
int T[1009][1009];
int solve(){
    int sal = sa.length(), sbl = sb.length();
    for(int a=0; a<=sal; a++){
        for(int b=0; b<=sbl; b++){
            if(a==0 || b==0){
                T[a][b] = 0;
            }else if(sa[a-1] == sb[b-1]){
                T[a][b] = 1 + T[a-1][b-1];
            }else{
                T[a][b] = max(T[a][b-1], T[a-1][b]);
            }
        }
    }
    return T[sal][sbl];
}
signed main(){
    int N;
    cin >> N;
    for(int i=0; i<N; i++){
        cin >> sa >> sb;
        cout << solve() << 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]; //　XiとYjのLCSの長さとする２次元配列
	int m = int(X.length());
	int n = int(Y.length());
	X =' '+X;
	Y =' '+Y;
	int maxl = 0;
	//初期化
	for (int i = 0;i<=m;i++) {
		c[i][0] = 0;
	}
	for (int j = 1;j<= n; j++) {
		c[0][j] = 0;
	}

	//Xｍ－１とYｎ、XmとYn-1どちらが長いかを調べる
	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 n; cin >> n;
	string S1, S2;

	for (int i = 0;i<n;i++) {
		cin >> S1 >> S2;
		cout << lcs(S1, S2) << endl;
	}
	return 0;

}

C++: #include<iostream>
#include<string>
#include<algorithm>
#define MAX 1001
using namespace std;

int main() {
    int n,mat[MAX][MAX];
    string s1,s2;
    cin >> n;
    for(int k=0;k<n;k++) {
        cin >> s1 >> s2;
        for(int i = 0; i < s1.size(); i++) {
            for(int j = 0; j < s2.size(); j++) {
                mat[i + 1][j + 1] = (s1[i] == s2[j] ? mat[i][j] + 1 : max(mat[i][j + 1], mat[i + 1][j]));
            }
        }
        cout << mat[s1.size()][s2.size()] << endl;
    }
}

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

static const int SIZE = 1000;

int max(int a, int b){
    return (a > b ? a : b);
}

void lcs(char *x, char *y){
    int dp[SIZE+1][SIZE+1];
    int xl,yl,res=0;
    
    xl = strlen(x);
    yl = strlen(y);

    for(int i=0; i<=xl; i++) dp[i][0] = 0;
    for(int i=0; i<=yl; i++) dp[0][i] = 0;


    for(int i=1; i<=xl; i++){
        for(int j=1; j<=yl; j++){
            if(x[i-1] == y[j-1]){
                dp[i][j] = dp[i-1][j-1]+1;
            }
            else dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
        }
    }

    cout<<dp[xl][yl]<<endl;
}

int main(){
    char x[SIZE],y[SIZE];
    int n;
    cin>>n;
    for(int i=0; i<n; i++){
        cin>>x>>y;
        lcs(x,y);
    }

    return 0;
}