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;

#define MAX 1000

int lcs(string x, string y) {
  int c[MAX + 1][MAX + 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<cstdio>
#include<algorithm>
using namespace std;

int mem[1005][1005];

void pre(int x,int y){
  for(int i=0;i<=x;i++){
    for(int j=0;j<=y;j++){
      mem[i][j]=0;
    }
  }

  return;
}

main(){
  int n;
  string temp;
  string x,y;

  cin >> n;
  
  for(int cnt=0;cnt<n;cnt++){
    
    x="0";
    y="0";
    cin >> temp;
    x+=temp;
    cin >> temp;
    y+=temp;

    pre((int)x.size(),(int)y.size());

    for(int i=1;i<=x.size();i++){
      for(int j=1;j<=y.size();j++){

	if(x[i]==y[j]){
	  mem[i][j]=mem[i-1][j-1]+1;
	}
	mem[i][j]=max(mem[i][j],max(mem[i-1][j],mem[i][j-1]));

      }
    }

    cout << mem[x.size()][y.size()]-1 << endl;
  }

  return (0);
}

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

int main() {
   int q;
   cin >> q;
   for (int i=0; i<q; i++) {
       string X,Y;
       cin >> X >> Y;
       int x=X.size();
       int y=Y.size();
       int dp[x][y];
       for (int j=0; j<x; j++) {
           for (int k=0; k<y; k++) {
               dp[j][k]=0;
           }
       }
       for (int j=0; j<x; j++) {
           for (int k=0; k<y; k++) {
               if (j==0) {
                   if (X[0]==Y[k]) dp[0][k]=1;
                   else dp[0][k]=dp[0][k-1];
                   continue;
               }
               if (k==0) {
                   if (X[j]==Y[0]) dp[j][0]=1;
                   else dp[j][0]=dp[j-1][0];
                   continue;
               }
               if (X[j]==Y[k]) dp[j][k]=max(dp[j-1][k-1]+1,max(dp[j-1][k],dp[j][k-1]));
               else dp[j][k]=max(dp[j-1][k],dp[j][k-1]);
           }
       }
       cout << dp[x-1][y-1] << endl;
   }
}

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

#include <string.h>

using namespace std;

typedef long long ll;

template<class T>
inline bool chmax(T &a, T b) {
    if(a < b) {
        a = b;
        return true;
    }
    return false;
}

template<class T>
inline bool chmin(T &a, T b) {
    if(a > b) {
        a = b;
        return true;
    }
    return false;
}

const int MAX_S = 1000;

int solve(int (*dp)[MAX_S + 1][MAX_S + 1],
        const char *x, const int xlen, const char *y, const int ylen) {
    for (int i = 1; i <= ylen; i++) {
        for (int j = 1; j <= xlen; j++) {
            chmax((*dp)[i][j], (*dp)[i - 1][j]);
            chmax((*dp)[i][j], (*dp)[i][j - 1]);
            if (y[i - 1] == x[j - 1]) {
                chmax((*dp)[i][j], (*dp)[i - 1][j - 1] + 1);
            }
        }
    }
    return (*dp)[ylen][xlen];
}

int main(void) {
    int Q;
    char X[1010], Y[1010];
    cin >> Q;

    for (int i = 0; i < Q; i++) {
        int xlen, ylen;
        int dp[MAX_S + 1][MAX_S + 1];

        cin >> X >> Y;
        xlen = strlen(X);
        ylen = strlen(Y);
        reverse((char *) &X, X + xlen);
        reverse((char *) &Y, Y + ylen);

        for (int i = 0; i <= ylen; i++) {
            for (int j = 0; j <= xlen; j++) {
                dp[i][j] = 0;
            }
        }

        cout << solve(&dp, X, xlen, Y, ylen) << endl;
    }
    
    return 0;
}

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

int main()
{
  int n;
  cin >> n;
  for (int k = 0; k < n; k++)
  {
    string X, Y;
    cin >> X >> Y;
    int N = X.size(), M = Y.size();
    vector<vector<int>> dp(N + 1, vector<int>(M + 1, 0));
    for (int i = 0; i < N; i++)
    {
      for (int j = 0; j < M; j++)
      {
        dp[i + 1][j + 1] = max(dp[i + 1][j], dp[i][j + 1]);
        if (X[i] == Y[j])
        {
          dp[i + 1][j + 1] = max(dp[i + 1][j + 1], dp[i][j] + 1);
        }
      }
    }
    cout << dp[N][M] << endl;
  }
}

C++: #include<iostream>
#include<cstring>
#include<cstdio>
#include<cstdlib>
#define xs 1000+5
#define ys 1000+5
using namespace std;
int l[xs][ys];
void lcs(string a,string b){
	int a_size=a.size();int b_size=b.size();
	a=' '+a;b=' '+b;
	for(int i=0;i<=a.size();i++){
		l[i][0]=0;
	}
	for(int i=0;i<=b.size();i++){
		l[0][i]=0;
	}
	for(int i=1;i<=a.size();i++){
		for(int j=1;j<=b.size();j++){
			if(a[i]==b[j]) {
				l[i][j]=l[i-1][j-1]+1;
			}else{
				l[i][j]=max(l[i-1][j],l[i][j-1]);
			}
		}
	}
}
int main(){
	int num;
	scanf("%d",&num);string a,b;
	for (int i=0;i<num;i++){
		
		cin>>a>>b;
		lcs(a,b);
		cout<<l[a.size()][b.size()]<<'\n';
	}
	
}