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;

static const int n = 1000;

int lcs(string X, string Y) {
	int c[n + 1][n + 1]; //　XiとYjのLCSの長さとする２次元配列
	int m = int(X.length());
	int n = int(Y.length());
	X =' '+X;
	Y =' '+Y;
	int maxl = 0;
	//初期化
	for (int i = 0;i<=m;i++) {
		c[i][0] = 0;
	}
	for (int j = 1;j<= n; j++) {
		c[0][j] = 0;
	}

	//Xｍ－１とYｎ、XmとYn-1どちらが長いかを調べる
	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][j - 1],c[i-1][j]);
            }
			maxl = max(maxl,c[i][j]);
		}
	}

	return maxl;
}

int main() {
	int n; cin >> n;
	string S1, S2;

	for (int i = 0;i<n;i++) {
		cin >> S1 >> S2;
		cout << lcs(S1, S2) << endl;
	}
	return 0;

}

C++: #include<iostream>
#include<string>
#include<algorithm>
#define MAX 1001
using namespace std;

int main() {
    int n,mat[MAX][MAX];
    string s1,s2;
    cin >> n;
    for(int k=0;k<n;k++) {
        cin >> s1 >> s2;
        for(int i = 0; i < s1.size(); i++) {
            for(int j = 0; j < s2.size(); j++) {
                mat[i + 1][j + 1] = (s1[i] == s2[j] ? mat[i][j] + 1 : max(mat[i][j + 1], mat[i + 1][j]));
            }
        }
        cout << mat[s1.size()][s2.size()] << endl;
    }
}

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

static const int SIZE = 1000;

int max(int a, int b){
    return (a > b ? a : b);
}

void lcs(char *x, char *y){
    int dp[SIZE+1][SIZE+1];
    int xl,yl,res=0;
    
    xl = strlen(x);
    yl = strlen(y);

    for(int i=0; i<=xl; i++) dp[i][0] = 0;
    for(int i=0; i<=yl; i++) dp[0][i] = 0;


    for(int i=1; i<=xl; i++){
        for(int j=1; j<=yl; 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[xl][yl]<<endl;
}

int main(){
    char x[SIZE],y[SIZE];
    int n;
    cin>>n;
    for(int i=0; i<n; i++){
        cin>>x>>y;
        lcs(x,y);
    }

    return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
using namespace std;
static const int N = 1000;

void lcs(string *x, string y){
  int c[N + 1][N + 1], max = 0, i, j;
  int m = x.size;
  int n = y.size;

  x = ' ' + x;
  y = ' ' + y;
 
  for(i = 1; i <= m; i++) c[i][0] = 0;
  for(i = 1; i <= n; i++) c[0][i] = 0;

  for(i = 1; i <= m; i++){
    for(j = 1; j <= m; j++){
      if(x[i] == y[j]) c[i][j] = c[i - 1][j - 1] + 1;
      else c[i][j] = max(c[i - 1][j - 1], c[i][j - 1]);
      max = max(max, c[i][j]);
    }
  }
  return max;
}

int main(){
  string x, y;
  int q, i;

  cin >> q;
  
  for(i = 0; i < q; i++){
    cin >> x >> y;
    cout << lcs(x, y) << endl;
  }
  return 0;
}

C++: #include<iostream>
#include<string>
#include<cstring>
#include<algorithm>
#define MAX_N 1000

int solve(std::string s,std::string t){
        int dp[MAX_N][MAX_N];
        memset(dp,0,sizeof(dp));
        int n,m;
        n=s.size(),m=t.size();
        for(int i=0;i<n;i++){
                for(int j=0;j<m;j++){
                        if(s[i]==t[j])
                                dp[i+1][j+1]=dp[i][j]+1;
                        else
                                dp[i+1][j+1]=std::max(dp[i][j+1],dp[i+1][j\
]);
                }
        }
        return dp[n][m];
}

int main(){
        int q;
        std::cin>>q;
        for(int i=0;i<q;i++){
                std::string s,t;
                std::cin >> s>>t;
                std::cout << solve(s,t) << std::endl;
        }
        return 0;
}

C++: #if 0

#endif

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

int main(){
	int q;
	string X,Y;
	string x,y;
	int L[1000][1000];
	int MAX;
	for(int i=0;i<1000;++i) //???????????\????????????L????????????
		for(int j=0;j<1000;++j)
			L[i][j]=0;
	
	cin >> q;
	for(int i=0;i<q;++i){
		cin >> X >> Y;
		for(int j=1;j<X.length()+1;++j)
			for(int k=1;k<Y.length()+1;++k){
				if(X[j-1]==Y[k-1])
					L[j][k]=1+L[j-1][k-1];
				else
					L[j][k]=max(L[j-1][k],L[j][k-1]);
				MAX = max(MAX,L[j][k]);
			}
	cout << MAX << endl;
	}
}

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

int main()
{
  int q;scanf("%d",&q);
  for(int Q=0;Q<q;Q++)
  {
  string X,Y;cin>>X>>Y;
  vector<vector<int>> dp(X.size()+1,vector<int>(Y.size()+1,0));
  for(int i=0;i<(int)X.size();i++)for(int j=0;j<(int)Y.size();j++)
  {
    if(X[i]==Y[j])dp[i+1][j+1]=dp[i][j]+1;//max({dp[i][j]+1,dp[i][j+1],dp[i+1][j]});
    else dp[i+1][j+1]=max(dp[i][j+1],dp[i+1][j]);
  }
  printf("%d\n",dp[X.size()][Y.size()]);
  }
}

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

int LCS(string p, string q) {
	vector<vector<int> > f(p.size()+1, vector<int>(q.size()+1,0));
	int t;
	for (int i = 1; i <= p.size(); i++) {
		for (int j = 1; j <= q.size(); j++) {
			if (p[i-1] == q[j-1])
				f[i][j] = f[i - 1][j - 1] + 1;
			else if (f[i][j - 1] > f[i - 1][j])
				f[i][j] = f[i][j - 1];
			else
				f[i][j] = f[i - 1][j];
		}
	}
	return f[p.size()][q.size()];
}

int main() {
	int n;
	string p[300];
	cin >> n;
	for (int i = 0; i < n; i ++) {
		cin >> p[2*i] >> p[2*i + 1];
	}
	for (int i = 0; i < n; i++) {
		cout << LCS(p[2*i], p[2 * i + 1])<<endl;
	}
	return 0;
}