Go: package main

import (
	"bufio"
	"os"
	"fmt"
	"strconv"
)

const max int = 1000 + 1
var A [][]int

func lcs(x, y string) int {
	x = " " + x
	y = " " + y
	for i:=0;i<len(x); i++ {
		for j:=0;j<len(y); j++ {
			A[i][j] = 0
		}
	}
	for i:=1; i<len(x); i++ {
		for j:=1; j<len(y); j++ {
			if x[i] == y[j] {
				A[i][j] = A[i-1][j-1] + 1
			} else if A[i-1][j] > A[i][j-1] {
				A[i][j] = A[i-1][j]
			} else {
				A[i][j] = A[i][j-1]
			}
		}
	}
	return A[len(x)-1][len(y)-1]
}

func nextInt(scanner *bufio.Scanner) int {
	scanner.Scan()
	num, _ := strconv.Atoi(scanner.Text())
	return num 
}

func nextStr(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}


func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	A = make([][]int, max)
	for i := range A {
		A[i] = make([]int, max)
	}
	n := nextInt(scanner)
	for i:=0; i<n; i++ {
		x := nextStr(scanner)
		y := nextStr(scanner)
		fmt.Printf("%d\n", lcs(x, y))
	}
}

C++: #include<iostream>
#include<queue>

using namespace std;
static const int N = 100;
static const int INFTY = (1<<21);

int n, M[N][N];
int d[N];

void bfs(int s) {
    queue<int> q;
    q.push(s);
    for(int i = 0; i < n; i++) d[i] = INFTY;
    d[s] = 0;
    int u;
    while( !q.empty() ) {
        u = q.front(); q.pop();
        for (int v = 0; v < n; v++) {
            if( M[u][v] == 0 || d[v]!= INFTY ) continue;
            d[v] = d[u] + 1;
            q.push(v);
        }
    }
    for (int i = 0; i < n; i++) {
        cout << i+1 << " " << (d[i] == INFTY ? (-1) : d[i]) << endl;
    }
}

int main() {
    int u, k, v;

    cin >> n;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            M[i][j] = 0;
        }
    }

    for(int i = 0; i < n; i++) {
        cin >> u >> k;
        u--;
        for (int j = 0; j < k; j++) {
            cin >> v;
            v--;
            M[u][v] = 1;
        }
    }

    bfs(0);

    return 0;
}

C++: #include<stdio.h>
#include<string.h>
    
int LCS(char *X, char *Y){
  int i,j,m,n,c[1001][1001];
  m = strlen(X);
  n = strlen(Y);
      
  for(i=0; i<m; i++){
    c[i][0] = 0;
  }
  for(j=0; j<n; j++){
    c[0][j] = 0;
  }
    
  for(i=1;i<m+1;i++){
    for(j=1;j<n+1;j++){
      if (X[i-1]==Y[j-1]) c[i][j]=c[i-1][j-1]+1;
      else if (c[i-1][j]>=c[i][j-1]) c[i][j]=c[i-1][j];
      else c[i][j]=c[i][j-1];
    }
  }
  return c[i-1][j-1];
}
    
int main(){
  int i, q;
  char X[1001], Y[1001];
      
  scanf("%d", &q);
  for(i=0; i<q; i++){
    scanf("%s", X);
    scanf("%s", Y);
    printf("%d\n", LCS(X, Y));
    
  }
  return 0;
}

C++: #include<iostream>
#include<string>
#include<algorithm>
#define MAX 1000
using namespace std;

int LCS(string X, string Y) {
    int i, j, maxl=0;
    int C[MAX+1][MAX+1];

    int X_len = X.size();
    int Y_len = Y.size();
    X = ' ' + X;
    Y = ' ' + Y;
    for (i=0; i<=X_len; i++) C[i][0]=0;
    for (j=1; j<=Y_len; j++) C[0][j]=0;

    for (i=1; i<=X_len; i++) {
        for (j=1; j<=Y_len; j++) {
            if (X[i]==Y[j]) {
                C[i][j]=C[i-1][j-1]+1;
                maxl = max(C[i][j], maxl);
            } else C[i][j]=max(C[i-1][j], C[i][j]);
        }
    }

    return maxl;
}

int main() {
    int n, i;
    string X, Y;
    
    cin >> n;
    for (i=0; i<n; i++) {
        cin >> X >> Y;
        cout << LCS(X, Y) << endl;
    }

    return 0;
}

C++: #include <iostream>
#include <cstring>
#include <algorithm>
//#define Max 2000000
using namespace std;
int dp[1001][1001];
char x[1000],y[1000];
void init(){
    for(int i=0;i<1000;i++)
        for(int j=0;j<1000;j++)
            dp[i][j]=0;
}
void LCS(){
    int m=strlen(x);
    int r=strlen(y);
    for(int i=1;i<=m;i++)
        for(int j=1;j<=r;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]);
            }
        }
}
int main()
{
    int q;
    cin>>q;
    while((q--)>0){
        cin>>x;
        cin>>y;
        init();
        LCS();
        cout<<dp[strlen(x)][strlen(y)]<<endl;
    }
}

C++: // #Sazaの1日1AC
#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000000 + 7;
const long long INF = 9e18;
const double PI = 3.14159265358979323846;

//マクロ
//型エイリアス
using ll = long long;
using P = pair<long long, long long>;
using vl = vector<long long>;
using vvl = vector<vector<long long>>;
using vP = vector<pair<long long, long long>>;
//ショートカット
#define rep(i, n) for (int i = 0; i < n; i++)
#define rep2(i, k, n) for (int i = k; i < n; i++) //半開区間
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define pb push_back
#define mkp make_pair
//入力
#define vin(v, N) for (long long i = 0; i < N; i++) cin >> v.at(i)
#define lin(n)long long n;cin >> n
#define chin(x)char x;cin >> x;
#define sin(s)string s;cin >> s;
#define vlin(v, N)vector<long long> v(N);for (long long i = 0; i < N; i++)cin >> v.at(i)
#define max(a, b) max((ll)a, (ll)b)
#define min(a, b) min((ll)a, (ll)b)

//関数
//最大公約数
long long gcd(long long m, long long n){
  long long a = max(m, n);
  long long b = min(m, n);
  long long r = a % b;
  while (r != 0){
    a = b;
    b = r;
    r = a % b;
  }
  return b;
}
// 最小公倍数
long long lcd(long long m, long long n){
  return m * n / gcd(m, n);
}
//xのn乗
long long power(long long x, long long N){
  long long ret = 1;
  for (long long i = 0; i < N; i++)
    ret *= x;
  return ret;
}
//繰り返し二乗法
long long repeat_squaring(long long x, long long n){
  if (n == 0)
    return 1;
  else if (n % 2 == 0)
  {
    long long t = repeat_squaring(x, n / 2);
    return t * t % mod;
  }
  else
    return x * repeat_squaring(x, n - 1);
}
//素因数分解(mapで返す)
map<long long, long long> factor(long long p){
  ll p1 = p;
  map<long long, long long> ret;
  for (long long i = 2; i * i <= p1; i++)
  {
    while (p % i == 0)
    {
      ret[i]++;
      p /= i;
    }
  }
  if (p != 1)
    ret[p]++;
  return ret;
}
//素数判定
bool is_prime(long long N){
  for (long long i = 2; i * i <= N; i++)
  {
    if (N % i == 0)
      return false;
  }
  return true;
}
//最大値更新
void chmax(long long &a, long long b){
  a = max(a, b);
}
//最小値更新
void chmin(long long &a, long long b){
  a = min(a, b);
}

//構造体
//Union-Find木
struct UnionFind
{
  //メンバ変数
  vector<long long> par; //par[i]:=頂点iの親
  vector<long long> s;   //s[i]:=頂点iが属する集合の個数(iが根のとき)

  //コンストラクタ
  UnionFind(long long N) : par(N), s(N){
    for (long long i = 0; i < N; i++)
    {
      par[i] = i; //最初はすべてが根として初期化
      s[i] = 1;
    }
  }
  //メンバ関数
  //root(i):=頂点iの根
  long long root(long long i){
    if (par[i] == i)
      return i;
    par[i] = root(par[i]); //経路圧縮
    return root(par[i]);   //再帰
  }
  //size[i]:=iが属する集合の個数
  long long size(long long i){
    return s[root(i)];
  }
  //same(x,y) xとyが同じ根を持つか(同じ集合に含まれるか)
  bool same(long long x, long long y){
    return root(x) == root(y);
  }
  //unite(x,y) xの根をyの根に繋げる(集合を合併)
  void unite(long long x, long long y){
    if (!same(x, y)){
      long long rx = root(x);
      long long ry = root(y);
      par[rx] = par[ry];
      s[ry] = s[rx] + s[ry];
    }
  }
};
//Binary Indexed Tree
struct BIT{
  vector<long long> bit;
  long long N;

  BIT(long long n){
    N = n;
    bit.resize(N + 1);
  }

  void add(long long i, long long w){
    for (long long x = i; x <= N; x += x & -x){
      bit[x] += w;
    }
  }
  long long sum(long long i){
    long long ret = 0;
    for (long long x = i; x > 0; x -= x & -x){
      ret += bit[x];
    }
    return ret;
  }
};
/////////////////⊂('ω'⊂ )))Σ≡GO!/////////////////



int main(){
  //doubleの桁数
  cout << fixed << setprecision(10);

  lin(q);
  rep(hoge, q){
    sin(x); sin(y);
    ll dp[1010][1010];

    ll N = x.size(), M = y.size();
    rep(i,N){
      rep(j,M){
        if(x[i] == y[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;
  }

  
}