Go: package main

/*
最長共通部分列
*/

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"os"
	"strconv"
	"strings"
)

func larger(l, r int) int {
	if l > r {
		return l
	}
	return r
}

var memo [1001][1001]int

func countLCS(x, y string) int {
	x = " " + x
	y = " " + y
	max := 0
	for xi := 1; xi < len(x); xi++ {
		for yi := 1; yi < len(y); yi++ {
			if x[xi] == y[yi] {
				memo[xi][yi] = memo[xi-1][yi-1] + 1
			} else {
				memo[xi][yi] = larger(memo[xi-1][yi], memo[xi][yi-1])
			}
			max = larger(max, memo[xi][yi])
		}
	}
	return max
}

func main() {
	scanner := makeScanner(1024)
	q := eGetInt(scanner)
	for i := 0; i < q; i++ {
		x := eGetLine(scanner)
		y := eGetLine(scanner)
		fmt.Println(countLCS(x, y))
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

type ints []int

func (s ints) String() string {
	var buf bytes.Buffer
	buf.WriteString("[")
	sep := ""
	for _, v := range s {
		buf.WriteString(fmt.Sprintf("%s%d", sep, v))
		sep = ", "
	}
	buf.WriteString("]")
	return buf.String()
}

func reverse(a ints) ints {
	r := make(ints, len(a))
	for i := 0; i < len(a); i++ {
		r[i] = a[len(a)-1-i]
	}
	return r
}
func max(a ints) (int, bool) {
	if len(a) == 0 {
		return 0, false
	}
	m := a[0]
	for _, e := range a {
		if e > m {
			m = e
		}
	}
	return m, true
}
func min(a []int) int {
	m := a[0]
	for _, v := range a {
		if v < m {
			m = v
		}
	}
	return m
}

func sum(a ints) int {
	if len(a) == 0 {
		return 0
	}
	sum := 0
	for _, e := range a {
		sum += e
	}
	return sum
}
func find(n int, a ints) int {
	for i, v := range a {
		if n == v {
			return i
		}
	}
	return -1
}

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

int cal(string na,string me){
  int l=na.size();
  int r=me.size();
  int h[1005][1005];
  for(int i=0;i<l;i++){
    for(int j=0;j<r;j++){
      h[i][j]=0;
    }
  }

  int ans=0;
  for(int i=1;i<=l;i++){
    for(int j=1;j<=r;j++){

      if(na[i-1]==me[j-1]) h[i][j]=h[i-1][j-1]+1;
      else h[i][j]=max(h[i][j-1],h[i-1][j]);

      ans=max(ans,h[i][j]);
    }
  }
  return ans;
}

int main(){
  int n,ans=0;
  cin>>n;

  string na,me;
  for(int i=0;i<n;i++){
    cin>>na>>me;
    ans=cal(na,me);
    cout<<ans<<endl;
  }

  return 0;
}

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


using namespace std;
const int MaxStringSize = 1000;
const int NullMemo = -1;

int calc_LCS(string str1, string str2) {
  // Memo[n][m] は str1.sub(0, n) と str2.sub(0, m)のLCSをmemoする。
  int memoLCS[str1.size() + 1][str2.size() + 1];

  for(int i = 0; i <= str1.size(); i++) {
    memoLCS[i][0] = 0;
  }
  for(int i = 0; i <= str2.size(); i++) {
    memoLCS[0][i] = 0;
  }

  for(int i = 1; i <= str1.size(); i++) {
    for(int j = 1; j <= str2.size(); j++) {
      if(str1[i - 1] == str2[j - 1]) {
        memoLCS[i][j] = memoLCS[i - 1][j - 1] + 1;
      } else {
        memoLCS[i][j] = max(memoLCS[i][j - 1], memoLCS[i - 1][j]);
      }
    }
  }

  return memoLCS[str1.size()][str2.size()];
}

int main() {
  int datasets_num;
  string str1;
  string str2;

  cin >> datasets_num;

  for(int i = 0; i < datasets_num; i++) {
    cin >> str1 >> str2;

    cout << calc_LCS(str1, str2) << endl;
  }
}

C++: #include<iostream>
#include<cstring>
#define LcsMaxLen 1005
using namespace std;
char sf[LcsMaxLen];
char ss[LcsMaxLen];
int mark[LcsMaxLen][LcsMaxLen]={0};
int LcsLen( int sfi,int ssi ){
	if(sfi<0||ssi<0)
		return 0;
	if(mark[sfi][ssi])return mark[sfi][ssi];
	if(sf[sfi]==ss[ssi]){
		mark[sfi][ssi] = LcsLen(sfi-1,ssi-1)+1;
		return mark[sfi][ssi];
	}
	else {
		mark[sfi][ssi] = max(LcsLen(sfi,ssi-1),LcsLen(sfi-1,ssi));
		return mark[sfi][ssi];
	}
} 
int main(){
	int n,len;
	cin>>n;
	while(n--){
	cin>>sf>>ss;
	len = max(strlen(sf),strlen(ss));
	for(int i = 0;i<len;++i)
		for(int j = 0;j<len;++j)
			mark[i][j]=0;
	cout<<LcsLen(strlen(sf)-1,strlen(ss)-1)<<endl;
	} 
	return 0;
}

C++: #include <iostream>

using namespace std;

int ans(string a, string b) {
  int n = a.size();
  int m = b.size();
  int memo[n+1][m+1];
  for (int i = 0; i <= n; i++) {
    for (int j = 0; j <= m; j++) {
      memo[i][j] = 0;
    }
  }

  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      int res = max(memo[i-1][j], memo[i][j-1]);
      if (a[i] == b[j]) {
        res = max(res, memo[i-1][j-1] + 1);
      } else {
        res = max(res, memo[i-1][j-1]);
      }
      memo[i][j] = res;
    }
  }
  
  return memo[n][m];
}

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

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

  return 0;
}

C++: #include<iostream>
#include<vector>
using namespace std;
int main()
{
	int kurikaeshi;
	vector<int> answer;
	cin >> kurikaeshi;
	for (int variable = 0;variable < kurikaeshi;++variable) {
		char X[1024], Y[1024];
		int LX = 0, LY = 0;
		vector<vector<int>> L;
		cin >> X >> Y;
		for (int i = 0;X[i] != 0;++i) LX += 1;
		for (int j = 0;Y[j] != 0;++j) LY += 1;
		L.resize(LX+1);
		for (int k = 0;k < LX + 1;++k) L[k].resize(LY+1);
		for (int i = 0;i<LX+1;++i) {
			for (int j = 0;j<LY+1;++j) {
				if (i == 0 || j == 0) {
					L[i][j] = 0;
				}
				else if (X[i-1] == Y[j-1]) {
					L[i][j] = L[i][j-1] + 1;
				}
				else {
					L[i][j] = L[i-1][j] > L[i][j-1] ? L[i-1][j] : L[i][j-1];
				}
			}
		}
		answer.push_back(L[LX][LY]);
	}
	for (int variable = 0;variable < kurikaeshi;++variable) {
		cout << answer[variable] << endl;
	}
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#include<numeric>
#include<string>
#include<cmath>
#include<set>
#include<queue>
#include<bitset>
#include<iomanip>
#include<cctype>
using namespace std;
const int inf = 1001001000;

void print(vector<vector<int>> a){
	for (int i=0;i<a.size();i++){
		for (int j=0;j<a[i].size();j++){
			cout << a[i][j] << " ";
		}
		cout << endl;
	}
}

void print(vector<int> a){
    int n = a.size();
    for (int j=0;j<n;j++) {
        if (j != n-1) cout << a[j] << " ";
        else cout << a[j] << endl;
    }
}

int main(){
    int q; cin >> q;
    for (int i = 0; i < q; i++){
        string a, b; cin >> a >> b;
        vector<vector<int>> dp(a.size()+1,vector<int>(b.size()+1,0));
        for (int k = 1; k < a.size()+1; k++){
            for (int l = 1; l < b.size()+1; l++){
                if (a[k-1] == b[l-1]){
                    dp[k][l] = max({dp[k-1][l-1]+1,dp[k-1][l],dp[k][l-1]});
                }
                else dp[k][l] = max(dp[k-1][l],dp[k][l-1]);
            }
        }
        cout << dp[a.size()][b.size()] << endl;
    }

    return 0;
}