Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	Q := sc.nextInt()
	for q := 0; q < Q; q++ {
		X, Y := sc.nextStr(), sc.nextStr()
		xLen, yLen := len(X), len(Y)
		dp := make([][]int, xLen+1)
		for i := 0; i <= xLen; i++ {
			dp[i] = make([]int, yLen+1)
		}
		for x := 0; x <= xLen; x++ {
			for y := 0; y <= yLen; y++ {
				if x == 0 || y == 0 {
					dp[x][y] = 0
				} else if X[x-1] == Y[y-1] {
					dp[x][y] = dp[x-1][y-1] + 1
				} else {
					dp[x][y] = max(dp[x-1][y], dp[x][y-1])
				}
			}
		}
		fmt.Fprintln(wtr, dp[xLen][yLen])
	}

	wtr.Flush()
}

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;
}

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

void lcs(string *x, string y){
  int c[N + 1][N + 1], max = 0, i, j;
  int m = x.size;
  int n = y.size;

  x = ' ' + x;
  y = ' ' + y;
 
  for(i = 1; i <= m; i++) c[i][0] = 0;
  for(i = 1; i <= n; i++) c[0][i] = 0;

  for(i = 1; i <= m; i++){
    for(j = 1; j <= m; j++){
      if(x[i] == y[j]) c[i][j] = c[i - 1][j - 1] + 1;
      else c[i][j] = max(c[i - 1][j - 1], c[i][j - 1]);
      max = max(max, c[i][j]);
    }
  }
  return max;
}

int main(){
  string x, y;
  int q, i;

  cin >> q;
  
  for(i = 0; i < q; i++){
    cin >> x >> y;
    cout << lcs(x, y) << endl;
  }
  return 0;
}

C++: #include<iostream>
#include<string>
#include<cstring>
#include<algorithm>
#define MAX_N 1000

int solve(std::string s,std::string t){
        int dp[MAX_N][MAX_N];
        memset(dp,0,sizeof(dp));
        int n,m;
        n=s.size(),m=t.size();
        for(int i=0;i<n;i++){
                for(int j=0;j<m;j++){
                        if(s[i]==t[j])
                                dp[i+1][j+1]=dp[i][j]+1;
                        else
                                dp[i+1][j+1]=std::max(dp[i][j+1],dp[i+1][j\
]);
                }
        }
        return dp[n][m];
}

int main(){
        int q;
        std::cin>>q;
        for(int i=0;i<q;i++){
                std::string s,t;
                std::cin >> s>>t;
                std::cout << solve(s,t) << std::endl;
        }
        return 0;
}