Go: package main

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

type Position struct {
	X int
	Y int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}
	for i := 0; i < n; i++ {
		strX := nextText(sc)
		strY := nextText(sc)
		fmt.Println(calcLcs(strX, strY))
	}
}

func calcLcs(strX, strY string) int {
	return lcs(strX, strY, Position{0, 0}, make(map[Position]int))
}

func lcs(strX string, strY string, position Position, memo map[Position]int) int {
	if position.X >= len(strX) || position.Y >= len(strY) {
		return 0
	}
	if v, ok := memo[position]; ok {
		return v
	}
	if strX[position.X] == strY[position.Y] {
		result := lcs(strX, strY, Position{position.X + 1, position.Y + 1}, memo)
		memo[position] = result + 1
		return memo[position]
	} else {
		result1 := lcs(strX, strY, Position{position.X + 1, position.Y}, memo)
		result2 := lcs(strX, strY, Position{position.X, position.Y + 1}, memo)
		var result int
		if result1 > result2 {
			result = result1
		} else {
			result = result2
		}
		memo[position] = result
		return result
	}
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

C++: #include <iostream>
#include <string>
using namespace std;
 
int lcs(string X, string Y) {
int max = 0;
int n = X.size();
int m = Y.size();
int dp[1000+1][1000+1];
 
X = ' '+X;
Y = ' '+Y;
 
for(int i = 1;i <= n; i++)
dp[i][0] = 0;
 
for(int i = 1; i <= m; i++)
dp[0][i] = 0;
 
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= m; 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];
 
if(max < dp[i][j])
max = dp[i][j];
}
}
 
return max;
}
 
int main() {
int N;
cin >> N;
 
string X, Y;
for (int i = 0; i < N; i++) {
cin >> X >> Y;
 
cout << lcs(X, Y) << endl;
}
return 0;
}

C++: #include <stdio.h>

int judge(char A[], char B[]){
  int a=0, b=0, sw=0, ans=0;
  int i, j;
  int C[1001][1001];
  
  while(sw == 0){
    if(A[a] != '\0')
      a++;
    else
      sw = 1;
  }
  
  sw = 0;
  
  while(sw == 0){
    if(B[b] != '\0')
      b++;
    else
      sw = 1;
  }
  
  for(i=1; i<a+1; i++)
    C[i][0] = 0;
  for(i=1; i<b+1; i++)
    C[0][i] = 0;
  
  for(i=1; i<a+1; i++){
    for(j=1; j<b+1; j++){
      if(A[i-1] == B[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];
      if(ans < C[i][j])
        ans = C[i][j];
    }
  }
  
  return ans;
}

int main(){
  char A[1000], B[1000];
  int n, i;
  
  scanf("%d", &n);
  
  for(i=0; i<n; i++){
    scanf("%s", A);
    scanf("%s", B);
    printf("%d\n", judge(A, B));
  }
  
  return 0;
}

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

using namespace std;

int lcs(const string & a, const string & b)
{
    vector<vector<int> > dp(a.size(), vector<int>(b.size()));

    for (size_t i = 0; i < dp.size(); ++i) {
        for (size_t j = 0; j < dp[0].size(); ++j) {
            if (a.at(i) == b.at(j)) {
                dp[i][j] = ((i == 0 || j == 0) ? 0 : dp[i - 1][j - 1]) + 1;
            } else {
                dp[i][j] = max(i == 0 ? 0 : dp[i - 1][j],
                               j == 0 ? 0 : dp[i][j - 1]);
            }
        }
    }

    return dp[a.length() - 1][b.length() - 1];
}

int main()
{
    int n;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        string a, b;
        cin >> a >> b;
        cout << lcs(a, b) << endl;
    }

    return 0;
}

C++: #include <iostream> 
#include <cstring> 
using namespace std;
int c[1001][1001];

int lcs(string x, string y)
{
    int maxl = 0;
    int m = x.length(), n = y.length();
 
    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][j-1], c[i-1][j]);
            }
            maxl = max(maxl, c[i][j]);
        } 
    } 
    return maxl;
}

int main()
{
    string x,y;
    int q;
    cin>>q;
    while(q--)
    {
        cin>>x>>y;
        int ans = lcs(x, y);
        cout<<ans<<endl;
    }
    return 0;
}

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

using namespace std;

void solve(){
	time_t start, end;

	string A;
	/*for (int i = 0; i < n; i++)*/ cin >> A;
	string B;
	cin >> B;
	int n = A.size(), m = B.size();
	vector<vector<int>> DP(n + 1, vector<int>(m + 1, 0));
	start = clock();
	
	//for (int i = 0; i < n; i++) DP[i][0] = 0;
	//for (int j = 0; j < m; j++) DP[0][j] = 0;

	for (int i = 1; i <= n; i++){
		for (int j = 1; j <= m; j++){
			if (A[i - 1] == B[j - 1]) DP[i][j] = DP[i - 1][j - 1] + 1;
			else DP[i][j] = max(DP[i - 1][j], DP[i][j - 1]);
		}
	}

	end = clock();

	cout << DP[n][m] << endl;

}

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

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

int dp[1002][1002];

int main()
{
	for (int i = 0; i < 1002; i++)
	{
		dp[0][i] = 0;
		dp[i][0] = 0;
	}
	int N;
	cin >> N;
	for (int i = 0; i < N; i++)
	{
		string str1, str2;
		cin >> str1 >> str2;
		for (int i = 1; i <= str1.size(); i++)
		{
			for (int j = 1; j <= str2.size(); j++)
			{
				int ans = 0;
				if (str1[i - 1] == str2[j - 1])ans++;
				dp[i][j] = min(max(dp[i - 1][j], dp[i][j - 1]) + ans,min(i,j));
			}
		}
		cout << dp[str1.size()][str2.size()] << 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 = 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 <vector>
#include <algorithm>
#include <string>

using namespace std;

int lcs(string& a, string& b)
{
    vector<vector<int>> dp(a.size() + 1, vector<int>(b.size() + 1, 0));

    for (size_t i = 1; i < dp.size(); ++i)
    {
        for (size_t j = 1; j < dp[0].size(); ++j)
        {
            if (a[i - 1] == b[j - 1])
            {
                dp[i][j] = dp[i - 1][j - 1] + 1;
            }
            else
            {
                dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]);
            }
        }
    }
    return dp[a.size()][b.size()];
}

int main()
{
    int q;
    cin >> q;

    for (int i = 0; i < q; ++i)
    {
        string a, b;
        cin >> a >> b;

        cout << lcs(a, b) << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

const int N = 1000;

int c[N + 1][N + 1];

int LCS(string X, string Y) {
  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 = 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) << "\n";
  }

  return 0;
}