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<string>
#include<algorithm>
using namespace std;

void lcs(string x,string y);

int main(){
	int n; cin>>n;
	string x,y;
	for(int i=0;i<n;i++){
		cin>>x>>y;
		lcs(x,y);
	}
	cin.get();cin.get();
}

void lcs(string x,string y){
	int m = x.size() , n = y.size();
	x = ' '+x; y = ' '+y;
	int **c;
	c = new int*[m+1]; for(int i=0;i<=m;i++) c[i] = new int[n+1];
	for(int i=0;i<=m;i++) c[i][0] = 0; for(int j=0;j<=n;j++) c[0][j] = 0;
	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;
				if(i==m&&j==n) cout<<c[i][j]<<endl;
			}else{
				c[i][j] = max(c[i-1][j],c[i][j-1]);
				if(i==m&&j==n) cout<<c[i][j]<<endl;
			}
		}
	}
	for(int i=0;i<=m;i++) delete [] c[i]; delete [] c;
}

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<bits/stdc++.h>
using namespace std;
static const int N=1001;
int lcs(string X,string Y){
  int c[N+1][N+1];
  int m=X.length();
  int n=Y.length();

  int max1=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 if(X[i]!=Y[j]){
	c[i][j]=max(c[i-1][j],c[i][j-1]);
      }
      max1=max(max1,c[i][j]);
    }
  }
  return max1;
}

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 <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 <iostream>
#include <string>
#include <algorithm>
using namespace std;
#define N (1000)
int lcs(string X,string Y){
    int c[N+1][N+1];
    int m=X.size();
    int n=Y.size();
    int maxv=0;
    X=' '+X;
    Y=' '+Y;
    for(int i=0;i<=m;i++)c[i][0]=0;
    for(int i=1;i<=n;i++)c[0][i]=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]);
            }
            maxv=max(maxv,c[i][j]);
        }
    }
    return maxv;
}

int main(void){
    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>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n)   FOR(i,0,n)
#define pb emplace_back
typedef long long ll;
typedef pair<int,int> pint;

int dp[1001][1001];
int main(){
    int n;
    string s,t;
    cin>>n;
    rep(i,n){
        cin>>s>>t;
        memset(dp,0,sizeof(dp));
        int ss=s.size(),st=t.size();
        rep(i,ss){
            rep(j,st){
                if(s[i]==t[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[ss][st]<<endl;
    }
    return 0;
}

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

int dp[150+1][150+1];

int lcsSub(std::string X, std::string Y, int i, int j){
	if (i==-1 || j==-1){
		return 0;
	}
	else{
		if(X[i]==Y[j]){
			if (dp[i][j] < 0){
				dp[i][j] = lcsSub(X, Y, i-1, j-1);
			}
			return dp[i][j]+1;
		}
		else{
			int up, left;
			if (dp[i+1][j] < 0){
				dp[i+1][j] = lcsSub(X, Y, i, j-1);
			}
			left = dp[i+1][j];
			if (dp[i][j] < 0){
				dp[i][j+1] = lcsSub(X, Y, i-1, j);
			}
			up = dp[i][j+1];
			
			return std::max(up, left);
		}
	}
}

int lcs(std::string X, std::string Y){
	int m,n,i,j;
	m = X.length();
	n = Y.length();
	for(i=0;i<m+1;i++){
		for(j=0;j<n+1;j++){
			dp[i][j] = -1;
		}
	}
	return lcsSub(X, Y, m-1, n-1);
}
int main(void){
	int i,q,n,m;
	std::string str1, str2;
	std::cin >> q;
	for (i=0;i<q;i++){
		std::cin >> str1;
		std::cin >> str2;
		std::cout << lcs(str1, str2) << std::endl;
	}
	return 0;
}