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<algorithm>
#include<vector>
#include<queue>
#include<string>
#include<set>
#include<map>

using namespace std;

const int MAX_SIZE = 1000;

int LCS(string& X, string& Y,int dp[MAX_SIZE][MAX_SIZE], int X_pos, int Y_pos) {
	if (Y_pos == Y.length() || X_pos == X.length()) {
		return 0;
	}
	int res;

	if (dp[X_pos][Y_pos + 1] == -1) {
		dp[X_pos][Y_pos + 1] = LCS(X, Y, dp, X_pos, Y_pos + 1);
	}
	res = dp[X_pos][Y_pos + 1];

	for (int i = X_pos; i < X.length(); i++) {
		if (X[i] == Y[Y_pos]) {
			if (dp[i + 1][Y_pos + 1] == -1) {
				dp[i + 1][Y_pos + 1] = LCS(X, Y, dp, i + 1, Y_pos + 1);
			}
			res = max(dp[i + 1][Y_pos + 1] + 1, res);
		}
	}
	return res;
}

int main() {
	int n;
	cin >> n;
	for (int i = 0; i < n; i++) {
		string X, Y;
		int dp[MAX_SIZE][MAX_SIZE];

		cin >> X;
		cin >> Y;

		for (int i = 0; i < X.length() + 1; i++) {
			for (int j = 0; j < Y.length() + 1; j++) {
				dp[i][j] = -1;
			}
		}

		cout << LCS(X, Y, dp, 0, 0) << endl;
	}
	return 0;
}

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

using namespace std;

int main(){
  string X,Y;
  int n;
  cin>>n;
  int ans[n];
  int l=0;
  for(int m=0;m<n;m++){
  cin>>X>>Y;

  int N[X.size()+1][Y.size()+1];

  for(int i=0;i<=X.size();i++){
    for(int j=0;j<=Y.size();j++){

      N[i][j]=1;
}
  }

  /*
  for(int i=0;i<X.size();i++){
    cout<<X[i]<<endl;
  }

for(int i=0;i<Y.size();i++){
    cout<<Y[i];
  }
  */

  
for(int i=0;i<=X.size();i++){
  N[i][0]=0;
  }

for(int i=0;i<=Y.size();i++){
  N[0][i]=0;
  }

 int point;

  for(int i=1;i<=X.size();i++){
    for(int j=1;j<=Y.size();j++){
      if(X[i-1]==Y[j-1]){
	point=1;
	
      }else{
	point=0;
      }
       N[i][j]=max({N[i-1][j],N[i][j-1],N[i-1][j-1]+point});
       point=0;
}
   
  }
  ans[l]=N[X.size()][Y.size()];
  l++;
  // cout<<N[X.size()][Y.size()]<<endl;
  /*
  //answer
  for(int i=0;i<=X.size();i++){
    for(int j=0;j<=Y.size();j++){

      cout<<N[i][j]<<" ";
      if(j==Y.size()){
	cout<<endl;
      }
}
  }
  */

  }
  cout<<ans[0]<<endl;
 cout<<ans[1]<<endl;
 cout<<ans[2]<<endl;
}

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

int preX[1020][30];
int dp[1020];

int main() {
	int q;
	cin >> q;
	for(int t = 0; t < q; t++) {
		string X, Y;
		for(int i = 0; i < 1020; i++) {
			for(int j = 0; j < 30; j++) {
				preX[i][j] = 0;
			}
			dp[i] = 0;
		}
		cin >> X >> Y;
		for(int i = 0; i < X.size(); i++) {
			for(int j = 0; j < 30; j++) {
				preX[i+1][j] = preX[i][j];
			}
			if(i > 0)
				preX[i+1][X[i-1]-'a'] = i;
		}
		for(int i = 0; i < Y.size(); i++) {
			for(int j = (int)X.size()-1; j >= 0; j--) {
				if(Y[i] == X[j])
					for(int k = 0; k < 30; k++)
						dp[j+1] = max(dp[j+1], dp[preX[j+1][k]] + 1);
			}
		}
		int res = 0;
		for(int i = 0; i < 1020; i++)
			res = max(res, dp[i]);
		cout << res << endl;
	}
}

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

using namespace std;

#define ll long long
typedef complex<double> P;

const int MAX_SIZE = 1001;
int q;
int dp[MAX_SIZE][MAX_SIZE] = {};

int main() {
  cin >> q;
  for (int i = 0; i < q; i++) {

    for (int j = 0; j < MAX_SIZE; j++) {
      dp[MAX_SIZE-1][0] = 0;
      dp[0][MAX_SIZE-1] = 0;
    }

    string a, b; cin >> a >> b;

    for (int j = 0; j < a.size(); j++) {
      for (int k = 0; k < b.size(); k++) {
        if(a[j] == b[k]) {
          dp[j+1][k+1] = dp[j][k] + 1;
        }
        else {
          dp[j+1][k+1] = max(dp[j][k+1], dp[j+1][k]);
        }
      }
    }

    cout << dp[a.size()][b.size()] << endl;
  }
}