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 <algorithm>
# include <vector>
# include <string>
# include <set>
# include <map>
# include <cmath>
# include <iomanip>
# include <functional>
# include <utility>
# include <stack>
# include <queue>
# include <list>
constexpr int MOD = 1000000007;
constexpr int INF = 2000000000;
using namespace std;

int lcs(string x, string y) {
	int c[1001][1001];
	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 n;
	cin >> n;
	string a, b;
	for (int i = 0; i < n; i++) {
		cin >> a >> b;
		cout << lcs(a, b) << endl;
	}
}

C++: #include <iostream>
#include <algorithm>
#include<string.h>
using namespace std;
int LCS(char *x,char *y);
char x[1001], y[1001];
int lcs[1001][1001];
int main()
{
	int q,i,j;

	cin >> q;
	for (i = 0; i < q; i++) {
		cin >> x;
		cin >> y;
		cout << LCS(x, y) << endl;
	}
}

int LCS(char *x, char *y)
{
	int i, j;
	int len_x, len_y;
	len_x = strlen(x);
	len_y = strlen(y);
	for (i = 0; i < len_x; i++) {
		for (j = 0; j < len_y; j++) {
			lcs[i][j] = '\0';
		}
		//cout << endl;
	}
	i = 0;
	while (x[i] != y[0]) {
		lcs[i][0] = 0;
		i++;
		if (i == len_x) break;

	}
	for (j = i; j < len_x; j++) {
		lcs[j][0] = 1;
	}
	while (y[i] != x[0]) {
		lcs[0][i] = 0;
		i++;
		if (i == len_y) break;
	}
	for (j = i; j < len_y; j++) {
		lcs[0][j] = 1;
	}

	for (i = 1; i < len_x; i++) {
		for (j = 1; j < len_y; j++) {
			if (x[i] == y[j]) {
				lcs[i][j] = lcs[i - 1][j - 1] + 1;
				//printf("lcs[%d][%d]=%d\n", i, j, lcs[i - 1][j - 1] + 1);
			}
			if (x[i] != y[j]) {
				lcs[i][j] = max(lcs[i - 1][j], lcs[i][j - 1]);
				//printf("lcs[%d][%d]=%d\n", i, j, max(lcs[i - 1][j], lcs[i][j - 1]));
			}
		}
	//cout << endl;

	}
	for (i = 0; i < len_x; i++) {
		for (j = 0; j < len_y; j++) {
			//printf("%d ", lcs[i][j]);
		}
		//cout << endl;
	}
	//cout << "len_x=" << len_x << endl << "len_y=" << len_y << endl;
			
	return lcs[i-1][j-1];
}

C++: #include <bits/stdc++.h>
using namespace std;

int dp[2000][2000];

int main(void){
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n; cin >> n;
  while(n--){
    string sa, sb; cin >> sa >> sb;
    memset(dp, 0, sizeof(dp));
    for(int i = 1; i <= sa.size(); i++){
      for(int j = 1; j <= sb.size(); j++){
        if(sa[i-1] == sb[j-1]){
          dp[i][j] = dp[i-1][j-1] + 1;
        }else{
          dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
        }
      }
    }
    cout << dp[sa.size()][sb.size()] << endl;
  }
  return 0;
}

C++: #include<bits/stdc++.h>
#define REP(i,n) for(long long i=0;i<n;++i)
#define FOR(i,a,b) for(long long i=a;i<b;++i)
using namespace std;
int main(){
    int q;
    scanf("%d",&q);
    string x,y;
    REP(i,q){
        cin>>x>>y;
        int dp[x.size()+1][y.size()+1];
        fill(dp[0],dp[x.size()],-1);
        REP(j,x.size()+1){
            REP(k,y.size()+1){
                if(j==0||k==0) dp[j][k]=0;
                else if(x[j]==y[k]) dp[j][k]=dp[j-1][k-1]+1;
                else dp[j][k]=max(dp[j][k-1],dp[j-1][k]);
            }
        }
        printf("%d\n",dp[x.size()][y.size()]);
    }
    return 0;
}

C++: #include <cmath>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <climits>
#include <map>
#include <list>
#include <stack>
#include <queue>
#include <vector>
#include <string>
#include <sstream>
#include <fstream>
#include <iostream>
#include <algorithm>
using namespace std;

int dat[1024][1024];
int getLcbLen(char* x, int xe, char* y, int ye){
	if(xe <= 0 || ye <= 0) return 0;
	if(dat[xe][ye] != -1) return dat[xe][ye];
	return dat[xe][ye] = (x[xe-1] == y[ye-1] ? 1 + getLcbLen(x, xe-1, y, ye-1) : max(getLcbLen(x, xe-1, y, ye), getLcbLen(x, xe, y, ye-1)));
}

int main() {
	int set;
	scanf("%d", &set);
	
	while(set--){
		char x[1024], y[1024];
		scanf("%s %s", x, y);
		int xe = (int)strlen(x), ye = (int)strlen(y);
		
		for(int i = 0; i < xe; i++){
			for(int k = 0; k < ye; k++){
				dat[i][k] = -1;
			}
		}
		printf("%d\n", getLcbLen(x, xe, y, ye));
	}
	return 0;
}

C++: #include <iostream>
#include <fstream>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <queue>
#include <stack>
#include <list>
#include <utility>
#include <cmath>
#include <sstream>
#define F first
#define S second
#define FOR(i,n) for(int i=0;i<(int)n;i++)
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define FORI(i,k,n) for(int i=k;i<(int)n;i++)
#define repp(i,k,n) for(int i=k;i<(int)n;i++)
using namespace std;
typedef pair<double, double> pdd;
typedef pair<int,int> pii;
const double EPS = 10e-6;
int c[2000][2000]={};
string x,y;
int dp(int o,int p)
{
	if(o==x.size()||p==y.size())return 0;
	if(c[o][p]!=-1)return c[o][p];
	int ans =0;
	if(x[o]==y[p])
	{
		ans=max(dp(o+1,p+1)+1,max(dp(o+1,p),dp(o,p+1)));
	}
	else ans=max(dp(o+1,p),dp(o,p+1));

	return c[o][p]=ans;
}

int main ()
{
	int n;
	cin>>n;
	rep(i,n)
	{
		
		cin>>x>>y;
		memset(c, -1, sizeof(c));
		cout<<dp(0,0)<<endl;;
	}



}

C++: #include "bits/stdc++.h"
using namespace std;

int main() {
	long long Q; cin >> Q;
	for (long long i = 0; i < Q; i++) {
		string X, Y; cin >> X >> Y;
		long long X_size = X.size(), Y_size = Y.size();
		vector<vector<long long>>DP(1100, vector<long long>(1100, 0));
		for (long long j = 0; j < X_size; j++) {
			DP.at(j).at(0) = 0;
		}
		for (long long j = 0; j < Y_size; j++) {
			DP.at(0).at(j) = 0;
		}
		for (long long j = 0; j < X_size; j++) {
			for (long long k = 0; k < Y_size; k++) {
				if (X.at(j) == Y.at(k)) DP.at(j + 1).at(k + 1) = max({ DP.at(j).at(k) + 1, DP.at(j).at(k + 1), DP.at(j + 1).at(k) });
				else DP.at(j + 1).at(k + 1) = max(DP.at(j).at(k + 1), DP.at(j + 1).at(k));
			}
		}
		cout << DP.at(X_size).at(Y_size) << endl;
	}
}

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

using namespace std;

int main(){

  int q;

  cin >> q;


  for(int k = 0; k < q; k++){
    string a, b;
    cin >> a >> b;
    int dp[a.size()][b.size()] = {};
    //初期設定
    if(a[0] == b[0]){
      dp[0][0] = 1;
    }
    for(int i = 1; i < a.size(); i++){
      if(a[i] == b[0] || dp[i-1][0] == 1){
        dp[i][0] = 1;
      }
    }
    for(int j = 1; j < b.size(); j++){
      if(a[0] == b[j] || dp[0][j-1] == 1){
        dp[0][j] = 1;
      }
    }
    for(int i = 1; i < a.size(); i++){
      for(int j = 1; j < b.size(); j++){
        if(a[i] == b[j]){
          if(dp[i-1][j-1] >= dp[i-1][j] && dp[i-1][j-1] >= dp[i][j-1]){
            dp[i][j] = dp[i-1][j-1]+1;

          }
          else{
            dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
          }
        }
        else{
          dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
        }
      }
    }
    cout << dp[a.size()-1][b.size()-1] << "\n";
  }

  return 0;
}