Go: package main

import (
	"bufio"
	"os"
	"io"
	"strconv"
	"math"
	"fmt"
)

var (
	nstr   func() string
	stdout *bufio.Writer
)

func init() {
	nstr = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func main() {
	defer stdout.Flush()

	n := nint()
	xList := make([]string, n)
	yList := make([]string, n)

	for i:=0;i<n ;i++  {
		xList[i] = nstr()
		yList[i] = nstr()
	}

	for i := 0; i<n	; i++  {
		fmt.Println(lcs(xList[i], yList[i]))
	}

}

func lcs(x string, y string) int{
	var m = len(x)
	var n = len(y)

	c := make([][]int, m+1)
	for i:= range c{
		c[i] = make([]int, n+1)
	}
	for i:=	1;i<=m ;i++  {
		for j:=1;j<=n ;j++  {
			if x[i-1] == y[j-1]{
				c[i][j] = c[i-1][j-1] + 1
			}else{
				c[i][j] = int(math.Max(float64(c[i-1][j]), float64(c[i][j-1])))
			}


		}
	}
	return c[m][n]

}


func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+11))
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

func nint64() int64 {
	i, err := strconv.ParseInt(nstr(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func nint() int {
	return int(nint64())
}

func getIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = nint()
	}
	return b
}

func getStringSlice(n int) []string {
	b := make([]string, n)
	for i := 0; i < n; i++ {
		b[i] = nstr()
	}
	return b
}

func gcd(x, y int) int {
	if y == 0 {
		return x
	}
	return gcd(y, x%y)
}

func lcm(x, y int) int {
	return x * y / gcd(x, y)
}

func contains(s []int, e int) bool {
	for _, a := range s {
		if a == e {
			return true
		}
	}
	return false
}

func bin(i int, prefix bool) string {
	i64 := int64(i)

	if prefix {
		return "0b" + strconv.FormatInt(i64, 2)
	} else {
		return strconv.FormatInt(i64, 2)
	}
}

func strReverse(s string) string {
	runes := []rune(s)
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}

	return string(runes)
}

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

const int N = 1000;

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

    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= n; 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]);
            }
        }
    }
    return c[m][n];
}

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

C++: #include<iostream>
using namespace std;
#include<algorithm>
#include<string>
int n, m;
string s, t;
int dp[1001][1001];
int main()
{
    int p;
    cin >> p;
    while(p>0)
    {
        p--;
        cin >> s >> t;
        int n = s.size();
        int m = t.size();
        for (int i = 1; i <= n; i++)
            dp[i][0] = 0;
        for (int i = 0; i < m; i++)
            dp[0][i] = 0;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                if (s[i] == t[i]) {
                    dp[i + 1][j + 1] = dp[i][j] + 1;
                }
                else {
                    dp[i + 1][j + 1] = max(dp[i][j + 1], dp[i + 1][j]);
                }
            }
        }
        cout << dp[n][m] << endl;
    }

}

C++: #include <cstdio>
#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 i, j;
    int maxlen = 0;
    X = " " + X;
    Y = " " + Y;

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

    for(i = 1 ; i <= m ; i++ ) {
        for(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][j-1], c[i-1][j]);
            }
            maxlen = max(maxlen, c[i][j]);
        }
    }
    return maxlen;
}

int main (void) {
    int N, i;
    string x, y;

    cin >> N;

    for(i = 0 ; i < N ; i++) {
        cin >> x;
        cin >> y;
        printf("%d\n", lcs(x,y));
    }

    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 = 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 <cstring>
using namespace std;

#define MIN(X,Y) ((X)<(Y)?(X):(Y))
#define MAX(X,Y) ((X)>(Y)?(X):(Y))

int dp[1001][1001];

int main(void){
  char x[1001], y[1001];
  int xln, yln;
  int dataNum;
  
  cin >> dataNum;
  for (int did=0; did<dataNum; did++){
    cin >> &(x[1]) >> &(y[1]);
    xln = strlen(x+1); yln = strlen(y+1);
    // dp tableの初期化
    for (int i=0; i<=xln; i++) dp[i][0] = 0;
    for (int j=0; j<=yln; j++) dp[0][j] = 0;
    // dp
    for (int i=1; i<=xln; i++){
      for (int j=1; j<=yln; j++){
        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]);
        }
      }
    }
/*    for (int i=0; i<=yln; i++){
      for (int j=0; j<=xln;j++){
        cout << dp[j][i] << " ";
      }
      cout << endl;
    }*/
    cout << dp[xln][yln] << endl;
  }
  return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int dp[1002][1002];

int main(){
	int n;cin >> n;
	string x, y;
	while(n--){
		fill((int*)dp, (int*)(dp+1002), 0);
		cin >> x >> y;
		for(int i = 1;i <= x.size();i++){
			for(int j = 1;j <= y.size();j++){
				if(x[i] == y[j])dp[i][j] = dp[i-1][j-1] + 1;
				else dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
			}
		}
		cout << dp[x.size()][y.size()] << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <climits>
#include <cstring>
#define rep(i, begin, end) for (__typeof(end) i = (begin) - ((begin) > (end)); i != (end) - ((begin) > (end)); i += 1 - 2 * ((begin) > (end)))

using namespace std;

const int N_MAX = 1000000;
string a[200];
string b[200];
int dp[10000][10000];

int solve(string a, string b){
  int N = a.length();
  int M = b.length();
  int n = max(N, M);
  rep(i, 0, n+1){
    rep(j, 0, n+1){
      dp[i][j] = 0;
    }
  }

  /*
    ...X
    .....X
    dp[i][j] = dp[i-1][j-1] + 1

    ...X
    .....Y
    dp[i][j] = max(dp[i-1][j], dp[i][j-1])
   */
  
  rep(row, 1, N+1){
    rep(col, 1, M+1){
      if(a[row-1] == b[col-1]){
	dp[row][col] = dp[row-1][col-1] + 1;
      }
      else{
	dp[row][col] = max(dp[row-1][col], dp[row][col-1]);
      }
    }
  }
  /*
  rep(row, 0, n+1){
    rep(col, 0, n+1){
      cout << dp[row][col] << " ";
    }
    cout << endl;
    }*/
  return dp[a.length()][b.length()];
}

int main(){
  int n;
  cin >> n;

  rep(i, 0, n){
    cin >> a[i];
    cin >> b[i];
  }
  
  rep(i, 0, n){
    cout << solve(a[i], b[i]) << endl;
  }
  
  return 0;
}