Go: package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

const N = 1001

func max(x, y int) int {
	if x > y {
		return x
	}
	return y
}

func lcs(x, y string) int {
	var c [N][N]int
	m := len(x)
	n := len(y)
	var maxl int

	x = " " + x
	y = " " + y

	for i := 1; i <= m; i++ {
		for 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
}

func answer(reader io.Reader) string {
	sc := bufio.NewScanner(reader)
	sc.Split(bufio.ScanWords)

	sc.Scan()
	q, _ := strconv.Atoi(sc.Text())

	var out bytes.Buffer
	for i := 0; i < q; i++ {
		sc.Scan()
		s1 := sc.Text()
		sc.Scan()
		s2 := sc.Text()
		out.WriteString(fmt.Sprintf("%d\n", lcs(s1, s2)))
	}
	return strings.TrimRight(out.String(), "\n")
}

func main() {
	fmt.Println(answer(os.Stdin))
}

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

using namespace std;

string s, t;

vector<vector<int>> memo(2000, vector<int>(2000,-1));

//s???i??????????????§???t???j??????????????§?????£?????¨??????LCS
int solve(int i, int j) {
	if (memo[i][j] != -1)return memo[i][j];

	if (i == 0 && j == 0)return (s[0] == t[0]);
	if (i == 0)return memo[i][j] = (bool)(solve(i, j - 1) + (s[i] == t[j]));
	if (j == 0)return memo[i][j] = (bool)(solve(i - 1, j) + (s[i] == t[j]));
	if (s[i] == t[j]) return solve(i - 1, j - 1) + 1;
	return memo[i][j] = max(solve(i - 1, j), solve(i, j - 1));
}

int main() {
	int n;
	cin >> n;
	while (n--) {
		cin >> s >> t;
		memo = vector<vector<int>>(2000, vector<int>(2000,-1));
		cout << solve(s.size() - 1, t.size() - 1) << endl;
	}
}

C++: #include <iostream>
#include <algorithm>
#include <stack>
#include <string>
#include <queue>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <vector>
#include <list>
#include <string.h>
#define _USE_MATH_DEFINES
#include <math.h>
#include <map>
#define INFTY (1<<30)
#define MAX 100000000

using namespace std;

int lcs(string x, string y) {
	int m = x.size(), n = y.size();
	int c[1000+1][1000+1];
	x = ' ' + x; y = ' ' + y;
	for( int i = 0; i <= m; i++) c[i][0] = 0;
	for( int j = 0; j <= n; j++) c[0][j] = 0;
	for( int i = 1; i <= m; i++) {
		for( int j = 0; j < n; j++) {
			if(x[i] == y[j]) c[i][j] = c[i-1][j-1];
			else if(c[i-1][j] >= c[i][j-1]) c[i][j] = c[i-1][j];
			else c[i][j] = c[i][j-1];
		}
	}
	return c[m][n];
}

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

	return 0;
}

C++: #include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
using namespace std;
const int N = 1010;
char x[N],y[N];
int c[N][N];
int lcs(char x[],char y[]){

    int lenx = strlen(x+1);
    int leny = strlen(y+1);

    for (int i=0; i<=lenx; i++) {
        c[i][0] = 0;
    }
    for(int j=1;j<=leny;j++){
        c[0][j] = 0;
        
    }

    for(int i=1;i<lenx;i++){
        for(int j=1;j<leny;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]);
        }
    }
    return c[lenx][leny];
}
int main(){
    int q;
    scanf("%d",&q);
    for (int i=0; i<q; i++) {
        gets(x+1);
        gets(y+1);
        cout<<lcs(x, y)<<endl;
    }
    return 0;
}

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

int main(){
  int dp[1000][1000]={0};
  int n,m=0;
  int ans[150];
  std::string str1,str2;
  std::cin>>n;
  for(int k=0;k<n;k++){
    std::cin>>str1>>str2;
    for(int i=1;i<=str1.size();i++){
      for(int j=1;j<=str2.size();j++){
	if(str1[i-1]==str2[j-1]){
	  dp[i][j]=dp[i-1][j-1]+1;
	}else{
	  dp[i][j]=std::max(dp[i-1][j],dp[i][j-1]);
	}
      }
    }
    ans[m]=dp[str1.size()][str2.size()];
    m++;
  }
  for(int i=0;i<m;i++){
    std::cout<<ans[i]<<"\n";
  }
  return 0;
}

C++: #include <cstdio>
#include <cstring>
#include <algorithm>

class TLcsSolver
{
    int FTable[1001][1001];
    const char* FArray1;
    const char* FArray2;
    const int Fn1;
    const int Fn2;

    int Count(int i, int j)
    {
        if(i == 0 || j == 0) return 0;
        if(FArray1[i-1] == FArray2[j-1]){
            return FTable[i-1][j-1] + 1;
        }
        return std::max(FTable[i-1][j], FTable[i][j-1]);
    }
    void Solve()
    {
        for(std::size_t i = 1; i < Fn1; ++i){
            for(std::size_t j = 1; j < Fn2; ++j){
                FTable[i][j] = Count(i, j);
            }
        }
    }
    void Print()const
    {
        for(std::size_t i = 0; i < Fn1; ++i){
            for(std::size_t j = 0; j < Fn2; ++j){
                printf("%d\t", FTable[i][j]);
            }
            printf("\n");
        }
    } 
public:
    TLcsSolver(const char* a, const char* b)
     : FArray1(a), FArray2(b)
     , Fn1(std::strlen(a)), Fn2(std::strlen(b))
    {
        Solve();
        // Print();
    }
    int Answer()const
    {
        return FTable[Fn1-1][Fn2-1];
    }
};

int main()
{
    int n;
    std::scanf("%d\n", &n);
    char a[1001];
    char b[1001];
    for(int i = 0; i < n; ++i){
        std::fgets(a, 1000, stdin);
        std::fgets(b, 1000, stdin);
        std::printf("%d\n", TLcsSolver(a, b).Answer());
    }
    return 0;
}