Go: package main

import "fmt"

func main() {
	var n int
	fmt.Scan(&n)

	for q := 0; q < n; q++ {
		var s1, s2 string
		fmt.Scan(&s1, &s2)
		s1, s2 = " " + s1, " " + s2

		dp := make([][]int, len(s1))
		for i := range dp {
			dp[i] = make([]int, len(s2))
		}

		max := 0

		for i := 1; i < len(s1); i++ {
			for j := 1; j < len(s2); 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])
				}
				max = Max(max, dp[i][j])
			}
		}

		fmt.Println(max)
	}
}

func Max(n ...int) int {
	max := n[0]
	for _, v := range n[1:] {
		if v > max {
			max = v
		}
	}
	return max
}

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;
}

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

int q;
int len[1005][1005];

int common(string a,string b,int m,int n){
    int i,j;
    for(i=0;i<=m;i++)len[i][0]=0;
    for(i=0;i<=n;i++)len[0][i]=0;
    for(i=0;i<m;i++){
        for(j=0;j<n;j++){
            if(a[i]==b[j])len[i+1][j+1]=len[i][j]+1;
            else len[i+1][j+1]=max(len[i+1][j],len[i][j+1]);
        }
    }
    return len[m][n];
}

int main()
{
    cin>>q;
    int i;
    for(i=0;i<q;i++){
        string a,b;
        cin>>a>>b;
        int m=a.length();
        int n=b.length();
        cout<<common(a,b,m,n)<<endl;
    }
    return 0;
}

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

int dp[1001][1001];
string str1, str2;
int n;

int solve(string str1, string str2) {
  memset(dp, 0, sizeof(dp));
  for(int r = 0; r < str2.size(); r++) {
    for(int c = 0; c < str1.size(); c++) {
      if(str2[r] == str1[c]) {
        dp[r + 1][c + 1] = dp[r][c] + 1;
      }
      else {
        dp[r + 1][c + 1] = max(dp[r + 1][c], dp[r][c + 1]);
      }
    }
  }
  return dp[str2.size()][str1.size()];
}

int main() {
  cin >> n;
  for(int i = 0; i < n; i++) {
    cin >> str1 >> str2;
    cout << solve(str1, str2) << endl;
  }
}

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

using namespace std;

string str1,str2;

int m[1000][1000];

int LCS(int i,int j){
  
  
  if(i==-1||j==-1){
    return 0;
  }else if(m[i][j]!=0){
    return m[i][j];
  }else if(str1[i]==str2[j]){
    m[i][j]=LCS(i-1,j-1)+1;
    return m[i][j];
  }else{
    m[i][j]=max(LCS(i-1,j),LCS(i,j-1));
    return m[i][j];
  }
  
}

int main(){
  int N;
  
  cin >> N;
  
  
  for(int i=0;i<N;i++){
    cin >> str1 >> str2;
    for(int j=0;j<1000;j++){
      for(int k=0;k<1000;k++){
        m[j][k]=0;
      }
    }
    cout << LCS(str1.size()-1,str2.size()-1) << endl;
  }
  return 0;
}