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>
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
#define SIZE 1005
#define INF 1000000005LL
//#define INF 1e18
#define MOD 1000000007

using namespace std;
typedef long long int ll;
typedef pair <int,int> P;

int dp[SIZE][SIZE];

void solve(){
  int n,m;
  string X,Y;
  cin >> X >> Y;
  n = X.size();
  m = Y.size();
  fill(dp[0],dp[0]+SIZE,0);
  rep(i,0,n) rep(j,0,m){
    int a=0,b=0,c=0;
    if(i>0)a = dp[i-1][j];
    if(j>0)b = dp[i][j-1];
    if(i>0 && j>0)c = dp[i-1][j-1];
    dp[i][j] = max({a,b,c+(X[i]==Y[j]?1:0)});
  }
  cout << dp[n-1][m-1] << endl;
}

int main(){

  int q;
  cin >> q;
  rep(i,0,q){
    solve();
  }

  return 0;
}

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

int dp[1001][1001];
int q;

void solve(){
  char x[1001],y[1001];
  scanf("%s %s",x,y);
  int lx = strlen(x);
  int ly = strlen(y);
  for(int i=0;i<=lx;i++){
    for(int j=0;j<=ly;j++){
      if(i==0||j==0) dp[i][j] = 0;
      else if(x[i]==y[j]) dp[i][j] = dp[i-1][j-1]+1;
      else dp[i][j] = max(dp[i][j-1],dp[i-1][j]);
    }
  }
  printf("%d\n",dp[lx][ly]);
  return;
}


int main(){
  scanf("%d",&q);
  for(int i=0;i<q;i++) solve();
  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 = 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 <cstdio>
#include <iostream>
#include <algorithm>
using namespace std;

int lcs(string s1, string s2) {
    int i, j, ret = 0;
    int n = s1.size();
    int m = s2.size();
    int c[n+1][m+1];
    s1 = ' ' + s1;
    s2 = ' ' + s2;

    for (i = 0; i <= n; i++) c[i][0] = 0;
    for (j = 1; j <= m; j++) c[0][j] = 0;

    for (i = 1; i <= n; i++) {
        for (j = 1; j <= m; j++) {
            if (s1[i] == s2[j]) {
                c[i][j] = c[i - 1][j - 1] + 1;
            }
            else {
                c[i][j] = max(c[i - 1][j], c[i][j - 1]);
            }
            ret = max(ret, c[i][j]);
        }
    }
    
    return ret;
}

int main(void) {
    int q, i;
    string s1, s2;
    
    scanf("%d", &q);
    for (i = 0; i < q; i++) {
        cin >> s1 >> s2;
        printf("%d\n", lcs(s1, s2));
    }

    return 0;
}

C++: // http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_10_C
#include <iostream>
#include <iomanip>
#include <algorithm>
#include <vector>

#define debug(x) cout << #x << "==" << x << endl;

using namespace std;

//??\???
#define MAX_LEN 1000
int N;
int dp[MAX_LEN + 1][MAX_LEN + 1];

void print_dp_table(int n, int m) {
  for(int i = 0; i < n; i++) {
    for(int j = 0; j < m; j++) {
      cout <<setw(2) << dp[i][j];
    }
    cout << "\n";
  }
  cout << "\n";
}

int main() {
  ios::sync_with_stdio(false);

  cin >> N;

  string s1, s2;

  while( cin >> s1 >> s2 ) {

    std::vector<char> a;
    std::vector<char> b;
    for(char& c : s1) {
      a.push_back(c);
    }
    for(char& c : s2) {
      b.push_back(c);
    }


    // dp ????????????????????????
    fill(dp[0], dp[MAX_LEN + 1], 0);

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

    // print_dp_table(a.size(), b.size());
    cout << dp[a.size()][b.size()] << endl;

  }

  return 0;
}

C++: #include <iostream>
#include <fstream>
#include <string>
#include <cmath>
#include <cstdio>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <utility>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <unordered_map>
#include <limits.h>
#include <bitset>
#define int long long
using namespace std;
using P = pair<int, int>;
using ll = long long;
using prique = priority_queue<int>;
const int MOD = 1000000007;
const int INF = LLONG_MAX/3;
const int MAX = 510000;
int dp[1100][1100];
signed main(){
    int n;
    cin>>n;
    for(int c=0;c<n;c++){
        string s,t;
        cin>>s>>t;
        int a=s.size(),b=t.size();
        for(int i=0;i<1100;i++){
            for(int j=0;j<1100;j++){
                dp[i][j]=0;
            }
        }
        for(int i=1;i<=a;i++){
            for(int j=1;j<=b;j++){
                if(s[i-1]==t[j-1]){
                    dp[i][j]=dp[i-1][j-1]+1;
                }else{
                    dp[i][j]=max(dp[i][j-1],dp[i-1][j]);
                }
            }
        }
        cout<<dp[a][b]<<endl;
    }
    return 0;
}