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<algorithm>
#include<bitset>
#include<iostream>
#include<iomanip>
#include<set>
#include<string>
#include<math.h>
#include<string>
#include<queue>
#include<vector>
using namespace std;
typedef long long int ll;
typedef pair<int, ll> P;

//--------------
//#define DEBUG
//--------------

#ifdef DEBUG
	#define debugprint(x) cout<<x<<" "
	#define debugendl cout<<endl
	#define debug(x) x
#else
	#define debugprint(x)
	#define debugendl
	#define debug(x)
#endif

class zahyo{
	public:
	int x;
	int y;
	zahyo(){
		x=0;
		y=0;
	}
	zahyo(int x_,int y_){
		x=x_;
		y=y_;
	}
	void print(){
		cout<<x<<" "<<y;
	}
	zahyo operator+(zahyo add){
		add.x=this->x+add.x;
		add.y=this->y+add.y;
		return add;
	}
	zahyo operator-(zahyo add){
		add.x=this->x-add.x;
		add.y=this->y-add.y;
		return add;
	}
	zahyo operator*(int t){
		zahyo temp;
		temp.x=this->x*t;
		temp.y=this->y*t;
		return temp;
	}
	zahyo operator%(int t){
		zahyo temp(this->x%t,this->y%t);
		return temp;
	}
	zahyo operator/(int t){
		zahyo temp(this->x/t,this->y/t);
		return temp;
	}
	bool operator==(const zahyo add) const{
		if(add.x==this->x and add.y==this->y){return true;}
		else{return false;}
	}
	bool operator!=(const zahyo add) const{
		if(add.x==this->x or add.y==this->y){return false;}
		else{return true;}
	}
	bool operator<(const zahyo add) const{
		if(this->x<add.x){return true;}
		else if(this->x==add.x and this->y<add.y){return true;}
		else{return false;}
	}
	bool operator>(const zahyo add) const{
		if(this->x>add.x){return true;}
		else if(this->x==add.x and this->y>add.y){return true;}
		else{return false;}
	}
	void input(){
		cin>>x>>y;
	}
};

bool IsInBoard(int x,int maxx, int y,int maxy){
	if(x>=0 and x<maxx and y>=0 and y<maxy){
		return true;
	}
	else{
		return false;
	}
}

int main(){
	int q;
	cin>>q;
	for(int i=0;i<q;i++){
		string x,y;
		cin>>x>>y;
		int dp[1001][1001]={};
		for(int j=1;j<=x.size();j++){
			for(int k=1;k<=y.size();k++){
				int same=0;
				if(x[j-1]==y[k-1]){
					same=1;
				}
				dp[j][k]=max(dp[j-1][k-1]+same,max(dp[j-1][k],dp[j][k-1]));
			}
		}
		cout<<dp[x.size()][y.size()]<<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];
	int m=X.size();
	int n=Y.size();
	int maxl=0;
	X=' '+X;
	Y=' '+Y;
	for(int i=1;i<=m;i++) c[i][0]=0;
	for(int j=1;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 <algorithm>
#include <iostream>
#include <string>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <deque>
#include <iomanip>
#include <limits>
#include <map>
#include <queue>
#include <stack>
#include <vector>

#define FOR(i,k,n) for(int (i) = (k); (i) < (n); ++(i))
#define rep(i,n) FOR(i,0,n)
#define pb push_back
#define all(v) begin(v), end(v)
#define debug(x) cerr << #x << ": " << x << endl
#define debug2(x,y) cerr << #x << ": " << x << ", " << #y << ": " << y << endl

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<i_i, int> p_i;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
template<class T> using vv=vector<vector<T>>;
typedef deque<int> di;
typedef deque<deque<int>> ddi;


int main() {
    int q;
    cin >> q;
    rep(i,q) {
        string x,y;
        cin >> x >> y;
        int dp[1050][1050] = {};
        rep(i,(int)x.length()) {
            rep(j,(int)y.length()) {
                if(i == 0 && j == 0) {
                    if(x[i] == y[j]) {
                        dp[i][j] = 1;
                    } 
                } else if(i == 0) {
                    if(x[i] == y[j]) {
                        dp[i][j] = 1;
                    } else { 
                        dp[i][j] = dp[i][j-1];
                    }
                } else if(j == 0) {
                    if(x[i] == y[j]) {
                        dp[i][j] = 1;
                    } else { 
                        dp[i][j] = dp[i-1][j];
                    }
                } else 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.length()-1][y.length()-1] << endl;
    }
	return 0;
}

C++: // input: alds1_10_c.in
#include<iostream>
#include<algorithm>
#define MAX_X 1000
#define MAX_Y 1000
using namespace std;

int c[MAX_X+1][MAX_Y+1];

int lcs(string& a, string& b) {
  a = ' ' + a;
  b = ' ' + b;

  for(int i=0; i<a.length(); i++) {
    c[i][0] = 0;
  }
  for(int i=0; i<b.length(); i++) {
    c[0][i] = 0;
  }

  for(int i=1; i<a.length(); i++) {
    for(int j=1; j<b.length(); j++) {
      if(a[i] == b[j]) {
        c[i][j] = c[i-1][j-1] + 1;
      } else {
        c[i][j] = max(c[i][j-1], c[i-1][j]);
      }
    }
  }

  return c[a.length()-1][b.length()-1];
}

int main() {
  int n;
  string a, b;
  cin >> n;
  for(int i=0; i<n; i++) {
    cin >> a >> b;

    cout << lcs(a, b) << endl;
  }
}

C++: #include <iostream>
#include <algorithm>
#include <string>
using namespace std;
const int MAX=1001;
int lcs(string X,string Y) 
{
	int i=0,j=0,c[MAX][MAX],x=X.length(),y=Y.length();
	for(i=0;i<=x;i++)c[i][0]=0;
	for(i=0;i<=y;i++)c[0][i]=0;
	for(i=1;i<=x;i++) 
	for(j=1;j<=y;j++) 
	if(X[i-1]==Y[j-1])c[i][j]=c[i-1][j-1]+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[x][y];
}
int main()
{
	int n;cin>>n;
	string X,Y;
	while(n--)
	{
		cin>>X>>Y;
		cout<<lcs(X,Y)<<endl;
	}
}