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 <vector>
#include <string>
#include <cmath>
#include <set>
#include <algorithm>
#include <array>
#include <complex>
#include <utility>
#include <map>
#include <inttypes.h>

int LCS(std::string s,std::string t){
    int n,m,c[n+1][m+1];
    n=s.size();
    m=t.size();
    int maxlen=0;
    for(int i=0;i<N;i++){
        c[i][0]=0; 
    }
    for(int i=0;i<M;i++){
        c[0][i]=0;
    }
    for(int i=0;i<n;i++){
        for(int j=0;j<m;j++){
            if(s[i]==t[i]){
                c[i][j]=c[i-1][j-1]+1;
            }else{
                c[i][j]=std::max(c[i-1][j],c[i][j-1]);
            }
            maxlen=std::max(c[i][j],maxlen);
        }
    }
    return max
}
int main(){
	int N;
    
    std::cin >> N;
    std::string s1,s2;
    for(int i=0;i<N;i++){
        std::cin >> s1 >> s2;
        std::cout << LCS(s1,s2) <<std::endl;
    }
        
    
    return 0;
}

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

int main() {
    int q, lcs[1100][1100], n, m;
    string X, Y;
    cin >> q;
    while(q--) {
        cin >> X >> Y;
        memset(lcs, 0, sizeof(lcs));
        n = X.size(), m = Y.size();
        X = ' ' + X, Y = ' ' + Y;
        for (int i = 0; i < n; ++i) {
            for (int j = 0; j < m; ++j) {
                if (X[i + 1] == Y[j + 1]) lcs[i + 1][j + 1] = lcs[i][j] + 1;
                else lcs[i + 1][j + 1] = max(lcs[i + 1][j], lcs[i][j + 1]);
            }
        }
        cout << lcs[n][m] << endl;
    }
    
    return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int dp[1002][1002];

int main(){
	int n;cin >> n;
	string x, y;
	while(n--){
		cin >> x >> y;
		for(int i = 1;i <= x.size();i++){
			for(int j = 1;j <= y.size();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]);
			}
		}
		cout << dp[x.size()][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;
  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;
  int a[N];
  
  for(int i = 0; i < n; i++){
    cin >> s1 >> s2;
    a[i] = lcs(s1, s2);
  }
  for(int i = 0; i < n; i++){
    cout << a[i] << endl;
  }
  
  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define inf 1e9
#define ll long long
#define ull unsigned long long
#define M 1000000007
#define P pair<int,int>
#define PLL pair<ll,ll>
#define FOR(i,m,n) for(int i=(int)m;i<(int)n;i++)
#define RFOR(i,m,n) for(int i=(int)m;i>=(int)n;i--)
#define rep(i,n) FOR(i,0,n)
#define rrep(i,n) RFOR(i,n,0)
#define all(a) a.begin(),a.end()
#define IN(n,a) rep(i,n){ cin>>a[i]; }
const int vx[4] = {0,1,0,-1};
const int vy[4] = {1,0,-1,0};
#define PI 3.14159265


void f(){
  string x,y;
  cin>>x>>y;
  int dp[1100][1100]={};
  
  rep(i,x.length()+1){
    rep(j,y.length()+1){
      if(i==0||j==0) continue;
      dp[i][j]=max(dp[i-1][j-1],dp[i][j-1]);
      if(x[i-1]==y[j-1]){
        FOR(k,j,y.length()){
          dp[i][k]=max(dp[i][k],dp[i][j]+1);
        }
      }
    }
  }

  cout<<dp[(int)x.length()][(int)y.length()]<<endl;
}


int main(){
  int q;
  cin>>q;
  while(q--){
    f();
  }
}

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

static const int N = 1000;

int lcs(string X, string Y) {
    int c[N + 1][N + 1] = {};
    int m = X.length();
    int n = Y.length();

    X = ' ' + X;
    Y = ' ' + Y;
    
    int maxl = 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() {
    int n;
    string X, Y;
    cin >> n;

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

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

string X;
string Y;

int calc(int x, int y){
    if (X[x] == '\0') return 0;
    int tmp1 = calc(x + 1, y);
    int tmp2 = 0;
    int y_next = Y.find(X[x], y);
    if (y_next == string::npos) {
        tmp2 = 0;
    } else {
        tmp2 = calc(x + 1, y_next + 1) + 1;
    }
    return max(tmp1, tmp2);
}

int main(){
    int q;
    cin >> q;
    for (int i = 0; i < q; i++) {
        cin >> X;
        cin >> Y;
        cout << calc(0, 0) << endl;
    }

    return 0;
}

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

int mazide(string a,string b){
  int c[1001][1001];
  int m=a.size(),n=b.size();
  int mx=0;
  a=' '+a;
  b=' '+b;
  for(int i=1;i<=m;i++){
    for(int j=1;j<=n;j++){
      if(a[i]==b[j]){
	c[i][j]=c[i-1][j-1]+1;
      }else{
	c[i][j]=max(c[i-1][j],c[i][j-1]);
      }
      mx=max(mx,c[i][j]);
    }
  }
  return mx;
}


int main(){
  int q;
  string s1,s2;
  cin>>q;
  for(int i=0;i<q;i++){
    cin>>s1>>s2;
    cout<<mazide(s1,s2)<<endl;
  }
  return 0;
}