Go: package main

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

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

func lcs(a, b string) int {
	lenA := len(a)
	lenB := len(b)
	dp := make([][]int, lenA+1)
	for i := range dp {
		dp[i] = make([]int, lenB+1)
	}

	for i := 1; i <= lenA; i++ {
		for j := 1; j <= lenB; j++ {
			if a[i-1] == b[j-1] {
				dp[i][j] = dp[i-1][j-1] + 1
			} else {
				dp[i][j] = max(dp[i][j-1], dp[i-1][j])
			}
		}
	}
	return dp[lenA][lenB]
}

func main() {
	n := scanInt()
	w := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		a := scanString()
		b := scanString()
		fmt.Fprintln(w, lcs(a, b))
	}
	w.Flush()
}

C++: #include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define NIL -1
#define MAX 1000

static const int N = 1000;

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

    int maxl = 0;
    X = ' ' + X;
    Y = ' ' + Y;

    for (int i = 0; i <= m; ++i){
        dp[i][0] = 0;
    }
    for (int j = 0; j <= n; ++j){
        dp[0][j] = 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 {
                dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
            }
            maxl = max(maxl, dp[i][j]);
        }
    }
    return maxl;
}


int main()
{
    int n;
    cin >> n;
    string X, Y;
    vector<int> v;

    rep(i, n)
    {
        cin >> X >> Y;
        v.push_back(lcs(X,Y));
    }

    rep(i, v.size()) cout << v[i] << 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], maxl = 0, i, j;
  int m = x.size();
  int n = y.size();

  x = ' ' + x;
  y = ' ' + y;
 
  for(i = 1; i <= m; i++) c[i][0] = 0;
  for(i = 1; i <= n; i++) c[0][i] = 0;

  for(i = 1; i <= m; i++){#include <iostream>

    for(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 q, i;

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

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

int main(int argc, char const *argv[]) {
  int q;
  std::cin >> q;
  for (size_t _ = 0; _ < q; _++) {
    std::string x, y;
    std::cin >> x;
    std::cin >> y;

    std::vector<std::vector<int> > dp(x.size()+1, std::vector<int>(y.size()+1));
    for (size_t ii=0; ii<x.size(); ++ii){
      for(size_t jj=0; jj<y.size(); ++jj){
        size_t i = ii + 1;
        size_t j = jj + 1;
        if (x[i]==y[j]){
          dp[i][j] = dp[i-1][j-1] + 1;
        }
        else{
          dp[i][j] = 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<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=0;i<=m;i++)c[i][0]=0;
    for(int i=1;i<=n;i++)c[0][i]=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;
}

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

#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)

const int MAX_L=1001;//?????????????????§??????

vector<vector<int> > DP(MAX_L, vector<int>(MAX_L, -1));
string A;//?????????????????????????????????
string B;

//A???a???????????¨????????\??????B???b???????????¨????????\??????????????§????????§?????¨????????????????????????????????????
//m?????????????????????????????±??????????????????
int dev(int a, int b){
	if(DP[a][b]<0){
		int maxi= 0;
		//???????????????????????§??????
		for(int c='a'; c<='z'; ++c){
			int posa = A.find(c,a);
			int posb = B.find(c,b);
			if(posa>=0 && posb>=0){
				int tmp = dev(posa+1,posb+1);
				maxi = max(maxi, tmp+1);
			}
		}
		for(int c='A'; c<='Z'; ++c){
			int posa = A.find(c,a);
			int posb = B.find(c,b);
			if(posa>=0 && posb>=0){
				int tmp = dev(posa+1,posb+1);
				maxi = max(maxi, tmp+1);
			}
		}
		DP[a][b]=maxi;
	}
	return DP[a][b];
}

int main(){
	int q;
	cin >> q;
	vector<int> ans(q);
	REP(i,q){
		REP(k,MAX_L){
			REP(l,MAX_L){
				DP[k][l] = -1;
			}
		}
		cin>>A>>B;
		ans[i]=dev(0,0);
	}
	REP(i,q){
		cout<<ans[i]<<endl;
	}
	return 0;
}

C++: #include<stdio.h>

void hantei(char x[], char y[]) {
  int xn = 0, yn = 0, flag = 0, c[1001][1001] = {0}, i, j;
  
  while (flag == 0)
  {
    if (x[xn] >= 97 && x[xn] <= 122)
    {
      xn++;
    }
    else
    {
      flag = 1;
    }
  }
  
  flag = 0;
  
  while (flag == 0)
  {
    if (y[yn] >= 97 && y[yn] <= 122)
    {
      yn++;
    }
    else
    {
      flag = 1;
    }
  }
  
  for (i = 1; i < xn + 1; i++)
  {
    for (j = 1; j < yn + 1; j++)
    {
      if (x[i - 1] == y[i - 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];
      }
    }
  }
  
  printf("%d\n", c[i][j]);
}

int main(void) {
  char x[1000], y[1000];
  int q, i;
  
  scanf("%d", &q);
  
  for (i = 0; i < q; i++)
  {
    scanf("%s", x);
    scanf("%s", y);
    hantei(x, y);
  }
  
  return 0;
}

C++: #include <iostream>
#include <iomanip>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <algorithm>
#include <cstdio>
#include <utility>
#include <string>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <deque>
#include <numeric>

using namespace std;

typedef uint64_t u64;
typedef int64_t s64;
typedef uint32_t u32;
typedef int32_t s32;
typedef vector<s32> vs32;
typedef vector<u32> vu32;
typedef vector<s64> vs64;
typedef vector<u64> vu64;

const double PI=3.14159265358979323846;

#define MAX(x, y) ((x) < (y) ? (y) : (x))
#define MIN(x, y) ((x) > (y) ? (y) : (x))

#define rep(i, N) for(int i = 0; i < N; ++i)

#define CEIL(x, y) (((x) + (y) - 1) / (y))
#define MOD 1000000007ULL

#define IN(l, r, x) ((l) <= (x) && (x) < (r))

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    int q;
    cin >> q;
    rep (_, q)
    {
        string x, y;
        cin >> x >> y;
        int nx = x.size();
        int ny = y.size();

        int dp[nx + 1][ny + 1];
        rep (i, nx + 1) rep (j, ny + 1) dp[i][j] = 0;

        rep (i, nx)
        {
            rep (j, ny)
            {
                if (x[i] == y[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[nx][ny] << "\n";
    }

    return 0;
}