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 <stdio.h>
#include <string.h>

int main(){
   char str_s[128], str_p[128];
   int i, j, c, h, n, m;
   scanf("%d",n);
   for(i=0;i < n;i++){
      scanf("%s",str_s);
      scanf("%s",str_p);
      n=strlen(str_s);
      m=strlen(str_p);
      c=0;
      h=0;
      for(i=0;i < n;i++){
         for(j=h;j < m;j++){
            if(str_s[i] ==str_p[j]){
               h=j+1;
               c++;
               break;
            }
         }
      }
      printf("%d\n, c");
   }

   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=1;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 <queue>
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;

int main(){
   int N;
   cin >> N;
   for(int i = 0;i < N;i++){
       string S,T;
       cin >> S >> T;
       int n = S.size(),m = T.size();
       int dp[1010][1010];
       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+1][j],dp[i][j+1]);
               }
           }
        }
    cout << dp[n][m] << endl;
   }
}

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

using namespace std;

using ll = long long;

#define REP(i,n) for(ll i=0;i<(ll)(n);i++)
#define REPD(i,n) for(ll i=n-1;i>=0;i--)
#define FOR(i,a,b) for(ll i=a;i<=(ll)(b);i++)
#define FORD(i,a,b) for(ll i=a;i>=(ll)(b);i--)

#define input(...) __VA_ARGS__; in(__VA_ARGS__)

template<class T>
void print(vector<T> a) {
  cout << "[ ";
  REP(i, a.size()) cout << a[i] << " ";
  cout << "]" << endl;
}

void print() {
  std::cout << std::endl;
}

template <class Head, class... Tail>
void print(Head&& head, Tail&&... tail) {
  std::cout << head << " ";
  print(std::forward<Tail>(tail)...);
}

void in() { }

template <class Head, class... Tail>
void in(Head&& head, Tail&&... tail) {
  cin >> head;
  in(std::forward<Tail>(tail)...);
}

vector<vector<ll>> table;
string A, B;
ll dfs(ll ai, ll bi) {
  if (table[ai][bi] != -1) return table[ai][bi];

  ll score = 0;
  if (ai < A.size() && bi < B.size() && A[ai] == B[bi])
    return table[ai][bi] = dfs(ai + 1, bi + 1) + 1;
  if (ai < A.size()) score = max(score, dfs(ai + 1, bi));
  if (bi < B.size()) score = max(score, dfs(ai, bi + 1));
  return table[ai][bi] = score;
}

int main() {
  ll input(n);
  REP (i, n) {
    table = vector<vector<ll>>(1000 + 1, vector<ll>(1000 + 1, -1));
    string input(a, b); A = a; B = b;
    cout << dfs(0, 0) << 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++ ) {
    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 q;
  cin >> q;

  for ( int i = 0; i < q; 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=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 <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <set>
#include <queue>
#include <map>
#include <memory.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ld> vld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define INF ((int)1e9)
#define INFLL ((ll)1e18)
#define MOD (1000000007LL)


int main(int argc, const char * argv[]) {
    int Q;
    string X, Y;
    cin >> Q;
    for (int q = 0; q < Q; ++q) {
        cin >> X >> Y;
        int DP[1001][1001];
        memset(DP, 0, sizeof(DP));
        for (int sx = 1; sx <= X.size(); ++sx) {
            for (int sy = 1; sy <= Y.size(); ++sy) {
                DP[sx][sy] = max(DP[sx-1][sy], DP[sx][sy-1]);
                if (X[sx] == Y[sy]) {
                    DP[sx][sy] = max(DP[sx][sy], DP[sx-1][sy-1]+1);
                }
            }
        }
        cout << DP[X.size()][Y.size()] << endl;
    }
    return 0;
}