Go: package main

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

var (
	nstr   func() string
	stdout *bufio.Writer
)

func init() {
	nstr = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func main() {
	defer stdout.Flush()

	n := nint()
	xList := make([]string, n)
	yList := make([]string, n)

	for i:=0;i<n ;i++  {
		xList[i] = nstr()
		yList[i] = nstr()
	}

	for i := 0; i<n	; i++  {
		fmt.Println(lcs(xList[i], yList[i]))
	}

}

func lcs(x string, y string) int{
	var m = len(x)
	var n = len(y)

	c := make([][]int, m+1)
	for i:= range c{
		c[i] = make([]int, n+1)
	}
	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{
				c[i][j] = int(math.Max(float64(c[i-1][j]), float64(c[i][j-1])))
			}


		}
	}
	return c[m][n]

}


func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+11))
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

func nint64() int64 {
	i, err := strconv.ParseInt(nstr(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func nint() int {
	return int(nint64())
}

func getIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = nint()
	}
	return b
}

func getStringSlice(n int) []string {
	b := make([]string, n)
	for i := 0; i < n; i++ {
		b[i] = nstr()
	}
	return b
}

func gcd(x, y int) int {
	if y == 0 {
		return x
	}
	return gcd(y, x%y)
}

func lcm(x, y int) int {
	return x * y / gcd(x, y)
}

func contains(s []int, e int) bool {
	for _, a := range s {
		if a == e {
			return true
		}
	}
	return false
}

func bin(i int, prefix bool) string {
	i64 := int64(i)

	if prefix {
		return "0b" + strconv.FormatInt(i64, 2)
	} else {
		return strconv.FormatInt(i64, 2)
	}
}

func strReverse(s string) string {
	runes := []rune(s)
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}

	return string(runes)
}

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

#define REP(i, n) for(int (i) = 0; (i) < (n); (i)++)

string str1, str2;
int dp[1001][1001];
int k;

int solve(int i, int j)
{
  if(dp[i][j] > 0)
    return dp[i][j];
  if(i >= str1.size() || j >= str2.size()){
    if(i < str1.size()){
      return solve(i + 1, k);
    }else{
      return 0;
    }
  }
  if(str1[i] == str2[j]){
    k = j + 1;
    int n, m = 0;
    for(int l = i + 1; l < str1.size(); l++){
      n = solve(l, j + 1);
      m = (n > m) ? n : m;
    }
    dp[i][j] = m + 1;
    return dp[i][j];
  }else{
    return solve(i, j + 1);
  }
}
  
int main()
{
  int q;
  cin >> q;
  cin.ignore();
  REP(i, q){
    getline(cin, str1);
    getline(cin, str2);
    if(str1.size() < str2.size())
      swap(str1, str2);
    fill(&dp[0][0], &dp[1001][0], -1);
    cout << solve(0, 0) << endl;
  }
}

C++: #include<iostream>
#include<stdio.h>
#include<string.h>
#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;
    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=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 <bits/stdc++.h>
#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <cmath>
#include <algorithm>
#include <map>
#include <iomanip>
#include <stdlib.h>
#include <stdio.h>
#include <queue>
#include <deque>
#include <set>
#include <stack>
#include <time.h>
 
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef pair<int, int> Pii;
typedef pair<int, ll> Pil;
typedef pair<ll, ll> Pll;
typedef pair<ll, int> Pli;

#define fi first
#define se second
#define mp make_pair
 
const ll MOD = 1e9 + 7;
const ll MOD2 = 998244353;
const ll INF = 1ll << 60;
const double PI = 2 * asin(1);

void yes() {printf("yes\n");}
void no() {printf("no\n");}
void Yes() {printf("Yes\n");}
void No() {printf("No\n");}
void YES() {printf("YES\n");}
void NO() {printf("NO\n");}

int Q, DP[1005][1005];
string X, Y;

int Solve(){
  int N = X.length(), M = Y.length();
  fill((int*)DP, (int*)(DP + N + 1), 0);

  for (int i = 1; i <= N; i++){
    for (int j = 1; j <= M; 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[N][M] << endl;
  return 0;
}

int main(){
  cin >> Q;
  for (int i = 0; i < Q; i++){
    cin >> X >> Y;
    Solve();
  }

  return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>

using namespace std;

int q;
char X[1000], Y[1000];
int dp[1001][1001];

int main(void) {

    scanf("%d", &q);

    for (int i = 0; i < q; ++i) {
        scanf("%s %s", X, Y);
        int xlen = strlen(X), ylen = strlen(Y);
        for (int x = 0; x < xlen; ++x) {
            for (int y = 0; y < ylen; ++y) {
                if (X[x] == Y[y]) {
                    dp[x + 1][y + 1] = dp[x][y] + 1;
                }
                else {
                    if (dp[x + 1][y] > dp[x][y + 1]) {
                        dp[x + 1][y + 1] = dp[x + 1][y];
                    }
                    else {
                        dp[x + 1][y + 1] = dp[x][y + 1];
                    }
                }
            }
        }
        printf("%d\n", dp[xlen][ylen]);
        memset(dp, 0, sizeof(int)*1001*1001);
    }
    printf("\n");
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

using ll = long long;
using Field = vector<vector<ll>>;
using Graph = vector<vector<ll>>;
using VI = vector<int>;
using VL = vector<ll>;
using VVL = vector<vector<ll>>;
using VC = vector<char>;
using PI = pair<int, int>;

#define FOR(i, s, n) for (int i = s; i < (n); i++)
#define REP(i, n) for (int i = 0; i < (n); i++)
#define ALL(x) x.begin(), x.end()

const long long INF = 1LL<<60;
const int mod = 1000000007;

template<class T> inline bool chmax(T &a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T &a, T b) { if (a > b) { a = b; return true; } return false; }

int q;


int main() {
    cin.tie(0);
    ios_base::sync_with_stdio(false);

    cin >> q;

    REP(_, q) {

        string A, B;
        vector<vector<int>> dp(1010, vector<int>(1010));

        cin >> A >> B;

        for (int i = 0; i < A.size(); i++) {
            if (A[i] == B[0]) dp[i][0] = 1;
            chmax(dp[i+1][0], dp[i][0]);
        }
        for (int i = 0; i < B.size(); i++) {
            if (A[0] == B[i]) dp[0][i] = 1;
            chmax(dp[0][i + 1], dp[0][i]);
        }
        
        for (int i = 1; i < A.size(); i++) {
            for (int j = 1; j < B.size(); j++) {
                if (A[i] == B[j]) {
                    chmax(dp[i][j], dp[i - 1][j - 1] + 1);
                } else {
                    chmax(dp[i][j], dp[i][j-1]);
                    chmax(dp[i][j], dp[i-1][j]);
                }
            }
        }



        cout << dp[A.size() - 1][B.size() - 1] << endl;


    }


    

    return 0;
}