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;
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 j = 0; 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() {
	string s1, s2;
	int n;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> s1 >> s2;
		cout << lcs(s1, s2) << endl;
	}

	return 0;
}

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

#define REP(i, n) for(int (i) = 0; (i) < (n); (i)++)

string str1, str2;
int dp[1001][1001];
int k;

int solve(int i, int j)
{
  if(dp[i][j] >= 0)
    return dp[i][j];
  if(i >= str1.size() || j >= str2.size()){
    if(i < str1.size()){
      dp[i][j - 1] = 0;
      return solve(i + 1, k);
    }else{
      return 0;
    }
  }
  if(str1[i] == str2[j]){
    k = j + 1;
    int n, m = 0;
    for(int l = i + 1; l < str1.size(); l++){
      n = solve(l, j + 1);
      m = (n > m) ? n : m;
    }
    dp[i][j] = m + 1;
    return dp[i][j];
  }else{
    return solve(i, j + 1);
  }
}
  
int main()
{
  int q, n, m, ans = 0;
  cin >> q;
  cin.ignore();
  REP(i, q){
    getline(cin, str1);
    getline(cin, str2);
    if(str1.size() < str2.size())
      swap(str1, str2);
    fill(&dp[0][0], &dp[1001][0], -1);
    REP(j, str1.size()){
      n = solve(j, 0);
      ans = (n > ans) ? n : ans;
    }
    cout << ans << endl;
    ans = 0;
  }
}

C++: #include <iostream>
#include <string>
#include <algorithm>
using namespace std;
#define N 1000

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=0;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(){
	string s1,s2;
	int n; cin>>n;
	for(int i=0;i<n;i++){
		cin>>s1>>s2;
		cout<<lcs(s1,s2)<<endl;
	}
	return 0;
}

C++: #include<iostream>
#include<vector>
#include<string>
using namespace std;
const int NIL = -1;
void SearchMaxSubString(string & a,string & b,
						vector<vector<int> > & maxlen,
						int s,
						int t)
{
	int lengthAB = 0;
	if (a[s] == b[t]) {
		lengthAB++;
		if ((s+1) < (int)a.size() && (t+1) < (int)b.size()) {
			if (maxlen[s+1][t+1] == NIL) {
				SearchMaxSubString(a,b,maxlen,s+1,t+1);
			}
			lengthAB += maxlen[s+1][t+1];
		}
		maxlen[s][t] = lengthAB;
	}
	else {
		int lengthA = 0;
		int lengthB = 0;
		if ((s+1) < (int)a.size()) {
			if (maxlen[s+1][t] == NIL) {
				SearchMaxSubString(a,b,maxlen,s+1,t);
			}
			lengthA = maxlen[s+1][t];
		}
		if ((t+1) < (int)b.size()) {
			if (maxlen[s][t+1] == NIL) {
				SearchMaxSubString(a,b,maxlen,s,t+1);
			}
			lengthB = maxlen[s][t+1];
		}
		maxlen[s][t] = std::max(lengthA,lengthB);
	}
}

int main(){
	int n;
	cin >> n;
	for(; n > 0; --n) {
		string a,b;
		cin >> a >> b;
		vector<vector<int> > maxlen;
		maxlen.resize(a.size());
		for(unsigned int i=0;i<a.size();++i) {
			maxlen[i].resize(b.size());
			for(unsigned j=0;j<maxlen[i].size();++j){
				maxlen[i][j] = NIL;
			}
		}
		SearchMaxSubString(a,b,maxlen,0,0);
		cout << maxlen[0][0] << std::endl;
	}
	return 0;
}

C++: #include<iostream>
#include<string>
int main(){
  int q;
  std::cin>>q;
  int i,j,k;
  std::string x,y;
  int a[1001][1001];
  int knum[q];
  for(i=0; i<1001; i++){
    for(j=0; j<1001; j++){
      a[i][j]=0;
    }
  }
  for(k=0; k<q; k++){
    std::cin>>x;
    std::cin>>y;
    for(i=1; i<x.size()+1; i++){
      for(j=1; j<y.size()+1; j++){
	if(x[i-1]==y[j-1]){
	  a[i][j]=a[i-1][j-1]+1;
	}else{
	  if(a[i-1][j]>a[i][j-1]){
	    a[i][j]=a[i-1][j];
	  }else{
	    a[i][j]=a[i][j-1];
	  }
	}
      }	
    }
    knum[k]=a[x.size()][y.size()];
  }
  for(k=0; k<q; k++){
    std::cout<<knum[k]<<"\n";
  }
  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 = 1; i <= m; i++) c[i][0] = 0;
    for (int j = 0; 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() {
    string s1, s2;
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> s1 >> s2;
        cout << lcs(s1, s2) << endl;
    }
    return 0;
}