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 <bits/stdc++.h>
using namespace std;
int q;
string x, y;
int m, n;
int a[1000][1000];
int main()
{
	cin >> q;
	for(int i=0; i<q; i++)
	{
		cin >> x >> y;
		m=x.size();
		n=y.size();
		if(x[0]==y[0])
		{
			a[0][0]=1;
		}
		else
		{
			a[0][0]=0;
		}
		for(int j=1; j<m+n-1; j++)
		{
			if((j<n)&&((x[0]!=y[j])&&(a[0][j-1]==0)))
			{
				a[0][j]=0;
			}
			else if(j<m)
			{
				a[0][j]=1;
			}
			if((j<m)&&((x[j]!=y[0])&&(a[j-1][0]==0)))
			{
				a[j][0]=0;
			}
			else if(j<m)
			{
				a[j][0]=1;
			}
			for(int k=max(1, j-n+1); k<min(j, m); k++)
			{
				if(x[k]==y[j-k])
				{
					a[k][j-k]=a[k-1][j-k-1]+1;
				}
				else
				{
					a[k][j-k]=max(a[k-1][j-k], a[k][j-k-1]);
				}
			}
		}
		cout << a[m-1][n-1] << endl;
	}
	return 0;
}

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

#define MAX 150
#define MAXL 1000

int C[MAXL + 1][MAXL + 1];

int lec(string X, string Y)
{
	int XL = X.length();
	int YL = Y.length();
	X = ' ' + X;
	Y = ' ' + Y;
	for (int i = 0; i <=XL; i++)
		C[i][0] = 0;
	for (int i = 0; i <=YL; i++)
		C[0][i] = 0;
	for (int i = 1; i <=XL; i++)
	{
		for (int j = 1; j <=YL; j++)
		{
			if (X[i] == Y[j])
			{
				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[XL][YL];
}

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

C++: #include <iostream>
#include <string>
#include <algorithm>
    using namespace std;
int lcs(string x,string y){
    int c[1010][1010];
    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(){
    int q;
    string x;
    string y;
    scanf("%d",&q);
    for (int i=0; i<q; i++) {
        cin>>x>>y;
        cout<<lcs(x, y)<<endl;
    }
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <queue>

#define INPUT_FROM_FILE (0) 
#if INPUT_FROM_FILE
#include <fstream>
#endif

int main(int argc, char **argv){
	std::string X, Y;
	int q;

#if INPUT_FROM_FILE
	std::ifstream ifs("test.txt");
	//FILE *fp = fopen("test.txt", "r");
#endif


#if INPUT_FROM_FILE
	std::getline(ifs, X);
#else
	std::getline(std::cin, X);
#endif
	q = std::stoi(X);

	for(int i = 0; i < q; i++){
		std::vector<std::vector<int> > dp;
#if INPUT_FROM_FILE
		std::getline(ifs, X);
		std::getline(ifs, Y);
#else
		std::getline(std::cin, X);
		std::getline(std::cin, Y);
#endif
		dp.resize(X.size() + 1);
		for(int i = 0; i < dp.size(); i++){
			dp[i].resize(Y.size() + 1, 0);
		}

		for(int i = 0; i < X.size(); i++){
			for(int j = 0; j < Y.size(); j++){
				if(X[i] == Y[j]){
					dp[i + 1][j + 1] = dp[i][j] + 1;
				}
				else{
					dp[i + 1][j + 1] = std::max(dp[i + 1][j], dp[i][j + 1]);
				}
			}
		}
		std::cout << dp[X.size()][Y.size()] << std::endl;
	}
	return 0;
}

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

int q;
string X,Y;
int L[1001][1001];

int max(int i,int j) {return i > j ? i : j;}

int getL(int i,int j) {
	if(L[i][j] != -1) return L[i][j];

	int res;

	if(i == 0 || j == 0) res = 0;
	else if(X[i - 1] == Y[j - 1]) res = 1 + getL(i - 1,j - 1);
	else res = max(getL(i,j - 1),getL(i - 1,j));

	L[i][j] = res;
	return res;
}

int main() {

	cin >> q;
	for(int i = 0;i < q;i++) {
		cin >> X >> Y;
		for(int j = 0;j <= X.size();j++) {
			for(int k = 0;k <= Y.size();k++) L[j][k] = -1;
		}
		cout << getL(X.size(),Y.size()) << endl;
	}
}

C++: #include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <cctype>
#include <string>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>
#include <functional>

using namespace std;
using ll = long long int;
#define rep(i,n) for(int i = 0; i < n; i++)
#define FOR(i, a, b)  for(int i = (a); i < (b) ; i++)
#define pb push_back
#define SORT(v,n) sort(v, v+n)
#define ALL(x) (x).begin(),(x).end()
#define debug(x) cerr << #x << ": " << x << '\n'
#define elif else if
#define itn ll
#define int ll
const int INF = 100100100;
const int MOD = (int)1e9 + 7;
const double EPS = 1e-9;
///                →,↑,←,↓,↗,↖,↙,↘
int dx[8] = { 1, 0, -1, 0, 1, -1, -1, 1 };
int dy[8] = { 0, 1, 0, -1, 1, 1, -1, -1 };


static const int N = 1000;

int lcs(string X, string Y) {
	int c[N + 1][N + 1];
	int maxl = 0;
	int i, j;
	int m = X.size();
	int n = Y.size();
	X = ' ' + X;
	Y = ' ' + Y;
	FOR(i, 1, m+1) {
		c[i][0] = 0;
	}
	FOR(i, 1, n+1) {
		c[0][i] = 0;
	}
	for (int i = 1; i <= m; i++) {
		for (int j = 1; j <= n; j++) {
			if (X[i] == X[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(c[i][j], maxl);
		}
	}
	return maxl;
}

signed main() {
	ios::sync_with_stdio(false);
	int n;
	string s1, s2;
	cin >> n;
	int i;
	rep(i, n) {
		cin >> s1 >> s2;
		cout << lcs(s1, s2) << "\n";
	}
	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 x, y;
  int n;
  cin >> n;
  for(int i = 0 ; i < n ; i++){
    cin >> x >> y;
    cout << lcs(x,y) << endl;
  }
return 0;

}