Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

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

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)
	for i := 0; i < n; i++ {
		x := getNextString(scanner)
		y := getNextString(scanner)

		fmt.Fprintln(writer, lcs(x, y))
	}

	writer.Flush()
}

func lcs(x, y string) int {
	lx := len(x)
	ly := len(y)
	dp := make([][]int, lx+1)
	for i := 0; i <= lx; i++ {
		dp[i] = make([]int, ly+1)
	}
	for i := 0; i < lx; i++ {
		for ii := 0; ii < ly; ii++ {
			if x[i] == y[ii] {
				dp[i+1][ii+1] = dp[i][ii] + 1
				continue
			}
			dp[i+1][ii+1] = dp[i][ii+1]
			if dp[i+1][ii] > dp[i+1][ii+1] {
				dp[i+1][ii+1] = dp[i+1][ii]
			}
		}
	}
	return dp[lx][ly]
}

C++: #include <iostream>
#include <cstring>
#define N 1000
using namespace std;

int C[N + 1][N + 1];
char X[N + 1];
char Y[N + 1];

int Longest(int n1, int n2)
{
    for (int i = 0; i <= n2; i++)
    {
        C[0][i] = 0;
    }
    for (int i = 0; i <= n1; i++)
    {
        C[i][0] = 0;
    }

    for (int i = 1; i <= n1; i++)
    {
        for (int j = 1; j <= n2; j++)
        {
            if (X[i - 1] == Y[j - 1])
            {
                C[i][j] = C[i - 1][j - 1] + 1;
            }
            else
            {
                C[i][j] = max(C[i][j - 1], C[i - 1][j]);
            }
        }
    }

    return C[n1][n2];
}

int main()
{
    int n;
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        cin >> X;
        cin >> Y;

        int n1 = strlen(X);
        int n2 = strlen(Y);
        cout << Longest(n1, n2) << endl;
    }

    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define rep(i,N) for(ll i=0;i<N;++i)
typedef long long int ll;
ll INF = 1LL<<60;

int dp[1010][1010];

int main(){
    ll N; cin >> N;
    rep(x,N){
        string s,t; cin >> s >> t;
        rep(i,s.size()){
            rep(j,t.size()){
                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[s.size()][t.size()] << endl;
    }
}

C++: #include<iostream>
#include<string>
#define lth 1000

using namespace std;

int main()
{
	int n, L[100][100], Lmax = 0, *save;
	string Xi[lth], Yi[lth];
	cin >> n;
	save = new int[n];
	for (int k = 0; k < n; k++)
	{
		Lmax = 0;
		string X, Y;
		cin >> X >> Y;
		for (int i = 0; i <= X.length(); i++)
		{
			if (i != 0)
				Xi[i] = X.substr(0, i );
		}
		for (int i = 0; i <= Y.length(); i++)
		{
			if (i != 0)
				Yi[i] = Y.substr(0, i );
		}
		for (int i = 0; i <= X.length(); i++)
			for (int j = 0; j <= Y.length(); j++)
			{
				if (i == 0 || j == 0)
					L[i][j] = 0;
				else if (Xi[i][i - 1] == Yi[j][j - 1])
				{
					L[i][j] = L[i - 1][j - 1] + 1;
				}
				else
				{
					L[i][j] = (L[i][j - 1] > L[i - 1][j]?L[i][j - 1] : L[i - 1][j]);
				}
				if (Lmax < L[i][j]) Lmax = L[i][j];
			}
		save[k] = Lmax;
	}
	for (int i = 0; i < n; i++)
		cout << save[i] << endl;
	//system("pause");
}

C++: #include<iostream>
#include<cstdio>
#include<algorithm>
#include<string>
#include<cstring>
using namespace std;
int dp[1000][1000];
string s1,s2;
int len1,len2;

int Str(){
	memset(dp,0,sizeof(dp));
	for(int i=1;i<=len1;i++)
		for(int j=1;j<=len2;j++){
			if(s1[i]==s2[j]){
				dp[i][j] = dp[i-1][j-1]+1;
			}else{
				dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
			}
		}
		return dp[len1][len2];
	}
	
	int main(){
		int n;
		cin>>n;
		while(n--){
			cin>>s1>>s2;
			len1=s1.size();
			len2=s2.size();
			s1=' '+s1;
			s2=' '+s2;
			cout<<Str()<<endl;
		}
		return 0;
	}

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

int lcs(string X, string Y) {
  int dp[1000 + 1][1000 + 1];
  int max = 0;
  int m = X.size();
  int n = Y.size();
  X = ' ' + X;
  Y = ' ' + Y;

  for (int i = 1; i <= m; i++)
    dp[i][0] = 0;

  for (int i = 1; i <= n; i++)
    dp[0][i] = 0;

  for (int i = 1; i <= m; i++) {
    for (int j = 1; j <= n; j++) {
      if (X[i] == Y[j])
	dp[i][j] = dp[i-1][j - 1] + 1;
      else if (dp[i - 1][j] >= dp[i][j - 1])
	dp[i][j] = dp[i - 1][j];
      else
	dp[i][j] = dp[i][j - 1];

      max = (max < dp[i][j]) ? dp[i][j] : max;
    }
  }

  return max;
}

int main() {
  int N = 0;
  cin >> N;

  for (int i = 0; i < N; i++) {
    string X, Y;
    cin >> X >> Y;

    cout << lcs(X, Y) << endl;
  }

  return 0;
}

C++: #include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;
const int maxx=1010;

int main (){
	int dp[maxx][maxx];
	string s,p;
	int q;
	cin>>q;
	while(q--){
		cin>>s>>p;
		int a=s.size(),b=p.size();
		for(int i=1;i<=a;i++) dp[i][0]=0;
		for(int i=1;i<=b;i++) dp[0][i]=0;
		for(int i=0;i<=a;i++){
			for(int j=0;j<=b;j++){
				if(s[i]==p[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[a][b]<<endl;
	}
	return 0;
}

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

#define FOR(i,a,b) for(int i=(a);i<(b);++(i))
#define REP(i,n) FOR(i,0,n)

#define dump(x) cerr << #x << " = " <<(x)<<endl;
#define debug(x) cerr << #x << " = " <<(x) << "(L" << __LINE__ << ")" << __FILE__ << endl;

using namespace std;

int lis(string x, string y){
 vector<vector<int>> v(x.size()+1, vector<int>(y.size()+1));
  REP(i,(int)x.size()+1){
    REP(j,(int)y.size()+1){
      if(i==0 or j==0) v[i][j]=0;
      else if(x[i-1]==y[j-1]){ 
        v[i][j] = v[i-1][j-1]+1;
      }
      else{
        v[i][j]=max(v[i][j-1],v[i-1][j]);
      }
    }
  }
  return v[x.size()][y.size()];
}

int main(void){
  int i,j,q;
  cin >>q;
  string x;
  string y;
  REP(i,q) {
    cin >> x>> y;
    cout << lis(x,y)<< endl;

  }
  return 0;
}

C++: #include <iostream>
#include <cmath>
#include <vector>

constexpr int MAX = 1000;
char ls[MAX];
char rs[MAX];
int table[MAX + 1][MAX + 1];


void calc_lcs() {
    scanf("%s", ls);
    scanf("%s", rs);
    int l_len = int(std::strlen(ls));
    int r_len = int(std::strlen(rs));
    for (int i = 0; i < l_len; i++) {
        table[i][0] = 0;
    }
    for (int i = 0; i < r_len; i++) {
        table[0][i] = 0;
    }

    for (int l_i = 1; l_i < l_len + 1; l_i++) {
        for (int r_i = 1; r_i < r_len + 1; r_i++) {
            if (ls[l_i - 1] == rs[r_i - 1]) {
                table[l_i][r_i] = table[l_i - 1][r_i - 1] + 1;
            } else {
                table[l_i][r_i] = std::max(table[l_i][r_i - 1], table[l_i - 1][r_i]);
            }
        }
    }
    std::cout << table[l_len][r_len] << std::endl;
}

int main() {
    int N;
    scanf("%d", &N);
    for (int i = 0; i < N; i++) {
        calc_lcs();
    }
}

C++: #include<bits/stdc++.h>
using namespace std;
#define inf 1e9
#define ll long long
#define ull unsigned long long
#define M 1000000007
#define P pair<int,int>
#define PLL pair<ll,ll>
#define FOR(i,m,n) for(int i=(int)m;i<(int)n;i++)
#define RFOR(i,m,n) for(int i=(int)m;i>=(int)n;i--)
#define rep(i,n) FOR(i,0,n)
#define rrep(i,n) RFOR(i,n,0)
#define all(a) a.begin(),a.end()
#define IN(n,a) rep(i,n){ cin>>a[i]; }
const int vx[4] = {0,1,0,-1};
const int vy[4] = {1,0,-1,0};
#define PI 3.14159265


void f(){
  string x,y;
  cin>>x>>y;
  int dp[1100][1100]={};
  
  rep(i,x.length()+1){
    bool flag=false;
    rep(j,y.length()+1){
      if(i==0||j==0) continue;
      int z= max(dp[i-1][j],dp[i][j-1]);
      if(!flag && x[i-1]==y[j-1]){
        z++;
        flag = true;
      }
      dp[i][j]=max(dp[i][j],z);
    }
  }

  cout<<dp[(int)x.length()][(int)y.length()]<<endl;
}


int main(){
  int q;
  cin>>q;
  while(q--){
    f();
  }
}