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 <bits/stdc++.h>
using namespace std;

#if __has_include("print.hpp")
  #include "print.hpp"
#endif

#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

typedef long long ll;
typedef pair<int, int> p;

vector<vector<int>> dp(2000, vector<int>(2000));

void solve(string s, string t){
  int n = int(s.size());
  int m = int(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] = max(dp[i][j+1], dp[i+1][j]);
      }
    }
  }

  cout << dp[n][m] << endl;
}

int main(){
  int n;
  cin >> n;
  for (int i = 0; i < n; i++)
  {
    string s, t;
    cin >> s >> t;
    solve(s, t);
  }
}

C++: #include<cstdio>
#include<iostream>
#include<algorithm>
#include<string>
using namespace std;
static const int N = 1000;
void lcs(string x, string y)
{
    int m = x.length(), n = y.length();
    int c[1001][1001]; //c[0][0] = 0;
    int maxv = 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]);
            maxv = max(maxv, c[i][j]);
        }
    }
    printf("%d\n", maxv);
}
int main()
{
    int q; string x, y;
    cin >> q;
    for(int i=0; i<q; i++)
    {
        cin >> x >> y;
        lcs(x, y);
    }
    //system("pause");
    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;    // X[0] に空白を挿入
    Y = ' ' + Y;    // Y[0] に空白を挿入
    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;
    for (int i = 0; i < n; i++) {
        cin >> s1 >> s2;
        cout << lcs(s1, s2) << endl;
    }

    return 0;
}

C++: #include<stdio.h>
#include<string.h>
#define max(a,b) ((a)>(b) ? (a):(b))
int dp[1001][1001];
int lcs(char *s,char *t){
    int i,j,ls,lt;

    ls=strlen(s);
    lt=strlen(t);
    for(i=0;i<ls;i++){
	for(j=0;j<lt;j++){
	    if(s[i]==t[j]) dp[i+1][j+1]=dp[i][j]+1;
	    else dp[i+1][j+1]=max(dp[i+1][j],dp[i][j+1]);
	}
    }
    return dp[ls][lt];
}
int main(){
    char s[1001],t[1001];
    int k;

    scanf("%d", &k);
    while(k--){
	scanf("%s%s", s, t);
	printf("%d\n",lcs(s,t));
    }

    return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<cstring>
#define _A_ true
using namespace std;
 
int main(){
  int n,AC=0,strA,strB;
  int dp[1010][1010];
  char *A = new char[1500];
  char *B = new char[1500];
 
  scanf("%d",&n);
  while(_A_){
    if(AC == n)break;
    scanf("%s",A);
    scanf("%s",B);
    for(int i=0;i<1010;i++)for(int j=0;j<1010;j++)dp[i][j]=0;
strA = strlen(A); 
strB = strlen(B);

    for(int i=0;i<strA;i++){
      for(int j=0;j<strB;j++){
    if(A[i] == B[j]){
      dp[i+1][j+1]=dp[i][j]+1;
    }
    else{
      if(dp[i+1][j] > dp[i][j+1]){
        dp[i+1][j+1]=dp[i+1][j];
      }
      else {
        dp[i+1][j+1] = dp[i][j+1];
      }
    }
      }
    }
    printf("%d\n",dp[strA][strB]);
    AC++;
  }
  delete [] A;
  delete [] B;
 
  return 0;
}

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


int S[1001][1001];

void prep(string str1, string str2, int len1, int len2)
{
	int a, b, i;
	S[0][0] = 0;
	for(i = 1; i <= len1; i++){ S[i][0] = 0; }
	for(i = 1; i <= len2; i++){ S[0][i] = 0; }
	for(a = 1; a <= len1; a++){
		for(b = 1; b <= len2; b++){
			if(str1[a - 1] == str2[b - 1]){ S[a][b] = 1; }else{ S[a][b] = 0; }
		}
	}
	return;
}

int main()
{
	int i, a, b, q, len1, len2;
	cin >> q;
	string str1, str2;

	for(i = 0; i < q; i++){
		cin >> str1 >> str2;
		len1 = str1.size();
		len2 = str2.size();
		prep(str1, str2, len1, len2);
		for(a = 1; a <= len1; a++){
			for(b = 1; b <= len2; b++){
				if(S[a][b]){ S[a][b] = S[a - 1][b - 1] + 1; }
				else{ S[a][b] = max(S[a - 1][b], S[a][b - 1]); }
			}
		}
		cout << S[len1][len2] << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <string>
using namespace std;
#define rep(i, p, n) for(int i = p; i < n; i++) 

int main() {
    int n;
    cin >> n;
    rep(i, 0, n) {
        string s, t;
        cin >> s >> t;
        int lcs[s.size()+1][t.size()+1];
        rep(j, 0, s.size()+1) {
            rep(k, 0, t.size()+1) {
                lcs[j][k] = 0;
            }
        }
        rep(j, 1, s.size()+1) {
            rep(k, 1, t.size()+1) {
                if(s[j-1] == t[k-1]) {
                    lcs[j][k] = max(lcs[j-1][k], max(lcs[j][k-1], lcs[j-1][k-1]+1));
                }
                else {
                    lcs[j][k] = max(lcs[j-1][k], lcs[j][k-1]);
                }
            }
        }

        cout << lcs[s.size()][t.size()] << endl;
        
    }

    return 0;
}

C++: #include <iostream>
#include <string>
#include <utility>
#include <algorithm>
#include <vector>
#include <cstdio>
#include <cstring>

using namespace std;

string s1,s2;

int L(int i,int j){
	if(i<0||j<0)return 0;
	else if(s1.at(i)==s2.at(j))return 1+L(i-1,j-1);
	else{
		int a=L(i,j-1);
		int b=L(i-1,j);
		return a>b?a:b;
	}
}

int main(){
	int q;
	cin>>q;
	for(int i=0; i<q; i++){
		cin>>s1>>s2;
		cout<<L(s1.size()-1,s2.size()-1)<<endl;
	}
}