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>b
using namespace std;
int main()
{
	int kurikaeshi;
	vector<int> answer;
	cin >> kurikaeshi;
	for (int variable = 0;variable < kurikaeshi;++variable) {
		char X[1024], Y[1024];
		int LX = 0, LY = 0;
		vector<vector<int>> L;
		cin >> X >> Y;
		for (int i = 0;X[i] != 0;++i) LX += 1;
		for (int j = 0;Y[j] != 0;++j) LY += 1;
		L.resize(LX+1);
		for (int k = 0;k < LX + 1;++k) L[k].resize(LY+1);
		for (int i = 0;X[i] != 0;++i) {
			for (int j = 0;Y[j] != 0;++j) {
				if (i == 0 || j == 0) {
					L[i][j] = 0;
				}
				else if (X[i] == Y[j]) {
					L[i+1][j+1] = L[i+1][j] + 1;
				}
				else {
					L[i+1][j+1] = L[i][j+1] > L[i+1][j] ? L[i][j+1] : L[i+1][j];
				}
			}
		}
		answer.push_back(L[LX][LY]+1);
	}
	for (int variable = 0;variable < kurikaeshi;++variable) {
		cout << answer[variable] << endl;
	}
}

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

using namespace std;

int results[1001][1001];

int lcs(string x, string y)
{
    // initialize
    for (int i = 0; i < 1001; ++i) {
        for (int j = 0; j < 1001; ++j)
            results[i][j] = 0;
    }

    int maxlcs = 0;
    for (int i = 1; i <= x.length(); ++i) {
        for (int j = 1; j <= y.length(); ++j) {
            if (x[i-1] == y[j-1])
                results[i][j] = results[i-1][j-1] + 1;
            else
                results[i][j] = max(results[i-1][j], results[i][j-1]);

            if (maxlcs < results[i][j])
                maxlcs = results[i][j];
        }
    }
    return maxlcs;
}

int main()
{
    int n;
    cin >> n;

    vector<string> x(n);
    vector<string> y(n);
    for (int i = 0; i < n; ++i)
        cin >> x[i] >> y[i];

    for (int i = 0; i < n; ++i)
        cout << lcs(x[i], y[i]) << '\n';
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)

int main() {
    int q;
    cin >> q;
    
    rep(i,q) {
        string X,Y;
        cin >> X >> Y;
        int lX=X.size(), lY=Y.size();
        vector<vector<int>> dp(lX+1, vector<int>(lY+1,0));

        rep(i,lX)
            rep(j,lY)
                if(X.at(i) == Y.at(j))
                    dp.at(i+1).at(j+1) = dp.at(i).at(j)+1;
                else
                    dp.at(i+1).at(j+1) = max(dp.at(i+1).at(j), dp.at(i).at(j+1));

        cout << dp.at(lX).at(lY) << 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=0;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 <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#define MAX 150
void solve(void);
int q,count[MAX][MAX]={},xlength,ylength;
char X[MAX],Y[MAX];

void solve(void){
  int i,j;

  for(i=1;i<=strlen(X);i++){
    for(j=1;j<=strlen(Y);j++){
      if(X[i-1]==Y[j-1]) count[i][j]=count[i-1][j-1]+1;
      else if(count[i-1][j]>=count[i][j-1]) count[i][j]=count[i-1][j];
      else count[i][j]=count[i][j-1];
    }
  }

  xlength=strlen(X);
  ylength=strlen(Y);
}
    

int main()
{
  int i;
  
  scanf("%d",&q);

  for(i=1;i<=q;i++){
    scanf("%s",X);
    scanf("%s",Y);
    solve();
    printf("%d\n",count[xlength][ylength]);
  }

  /*for(i=0;i<q;i++){
    printf("%d\n",count[][]);
    }*/

  return 0;
}

C++: #include <bits/stdc++.h>
#include<math.h>
#define rep(i,n) for (int i = 0; i < (n) ; ++i)
using namespace std;
using ll = long long ;
using P = pair<int, int> ;
#define PI 3.14159265358979323846264338327950

void C (string x, string y){
    int p = x.size() ;
    int q = y.size() ;
    vector<vector<int>> dp (p + 1 , vector<int> (q + 1)) ;
    rep(i, p){
        rep(j, q){
            if(x.at(i) == y.at(j)){
                dp[i+1][j+1] = dp[i][j] + 1 ;
            }
            else {
                dp[i+1][j+1] = max(dp[i][j+1], dp[i+1][j]) ;
            }
        }
    }
    cout << dp[p][q] << endl;
}

int main() {
    int n ; 
    cin >> n ;
    vector<string> s (n) ;
    vector<string> t (n);
    rep(i, n){
        cin >> s[i] ;
        cin >> t[i] ;
    }
    rep(k, n){
        C(s[k], t[k])  ;
    }
}