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 <bits/stdc++.h>

using namespace std;

#define FOR(i,s,e) for((i)=(s);(i)<(int)(e);(i)++)
#define REP(i,e) FOR(i,0,e)

#define all(o) (o).begin(), (o).end()
#define psb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))

typedef long long ll;
typedef pair<int, int> PII;

const double EPS = 1e-10;

const int N = 1000;
char s[N+1], t[N+1];
int ls, lt;
int q;
int dp[N+1][N+1];
//dp[i][j] = s[0]...s[i-1]??¨t[0]...t[j-1]???LCS
//(1<=i<=ls, 1<=j<=lt)

int main() {
  int i, j, k;
  scanf("%d ", &q);
  for (k=0; k<q; k++) {
    ls = lt = 0;
    memset(s, 0, sizeof(s)), scanf("%s ", s);
    memset(t, 0, sizeof(t)), scanf("%s ", t);
    while (s[ls]) ls++;
    while (t[lt]) lt++;

    memset(dp, 0, sizeof(dp));
    for (i=1; i<=ls; i++)
      for (j=1; j<=lt; j++) {
        if (s[i-1]==t[j-1])
          dp[i][j] = dp[i-1][j-1] + 1;
        else
          dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
      }

    printf("%d\n", dp[ls][lt]);
  }

  return 0;
}

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

static const int N = 1000;

int lcs(std::string X, std::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 = 0; i <= n; i++)
    {
        c[0][i] = 0;
    }

    for (int i = 1; i <= m; i++)
    {
        for (int j = 1; j <= n; j++)
        {
            if (X.at(i) == Y.at(j))
            {
                c[i][j] = c[i - 1][j - 1] + 1;
            }
            else
            {
                c[i][j] = std::max(c[i-1][j],c[i][j-1]) ;
            }
            maxl = std::max(maxl,c[i][j]) ;
        }
    }
    return maxl ;
}

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

C++: #include <stdio.h>
#include <iostream>
#include <algorithm>
??
using namespace std;
??
short checkTable[1001][1001];
??
int tmp_max=0;
??
??
void calc(int index,char pattern[],char to_search[],int to_search_length){
??
????????for(int i=to_search_length-1;i>=0;i--){
????????????????if(to_search[i]==pattern[index]){
????????????????????????checkTable[index][i]=1;
????????????????????????if(pattern[index+1]!='\0' && i < to_search_length-1){
????????????????????????????????checkTable[index][i] = checkTable[index+1][i+1] + checkTable[index][i];
????????????????????????}
????????????????}else{
????????????????????????if(i != to_search_length-1){
????????????????????????????????if(pattern[index+1] != '\0'){
????????????????????????????????????????checkTable[index][i]=(checkTable[index+1][i]>checkTable[index][i+1])
?????????????????????????????????????????????????????????checkTable[index+1][i]:checkTable[index][i+1];
??
????????????????????????????????}else{
????????????????????????????????????????checkTable[index][i]=(checkTable[index][i+1]>0)?checkTable[index][i+1]:0;
????????????????????????????????}
????????????????????????}else{
????????????????????????????????if(pattern[index+1] != '\0'){
????????????????????????????????????????checkTable[index][i]=(checkTable[index+1][i]>0)?checkTable[index+1][i]:0;
????????????????????????????????}else{
????????????????????????????????????????checkTable[index][i] = 0;
????????????????????????????????}
????????????????????????}
????????????????}
????????????????tmp_max = (tmp_max >= checkTable[index][i])?tmp_max:checkTable[index][i];
????????}
}
??
int main(){
??
????????int q,left_length,right_length;
????????char left[1001],right[1001];
??
????????scanf("%d",&q);
??
????????for(int i=0;i<q;i++){
????????????????left_length=0;
????????????????right_length=0;
????????????????scanf("%s %s",left,right);
????????????????for(int k=0;left[k]!='\0';k++)left_length++;
????????????????for(int k=0;right[k]!='\0';k++)right_length++;
??
????????????????if(right_length>=left_length){
??
????????????????????????for(int k=left_length-1;k>=0;k--)calc(k,left,right,right_length);
????????????????}else{
??
????????????????????????for(int k=right_length-1;k>=0;k--)calc(k,right,left,left_length);
????????????????}
????????????????printf("%d\n",tmp_max);
????????????????tmp_max=0;
????????}
??
????????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 res = 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]);

			}
			res = max(res, c[i][j]);
		}
	}
	return res;
}

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;
}