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 <cstring>

using namespace std;

int main(void)
{
    int q;
    char x[1001], y[1001];
    int table[1001][1001];
    
    cin >> q;
    for (int i = 0; i < q; i++) {
	cin >> x >> y;
	int xl = strlen(x), yl = strlen(y);

	for (int i = 0; i < xl; i++)
	    table[i][0] = x[i] == y[0];
	for (int j = 0; j < yl; j++)
	    table[0][j] = x[0] == y[j];

	for (int i = 1; i < xl; i++)
	    for (int j = 1; j < yl; j++)
		if (x[i] == y[j])
		    table[i][j] = 1 + table[i-1][j-1];
		else
		    table[i][j] = max(table[i-1][j], table[i][j-1]);

	cout << table[xl - 1][yl - 1] << endl;
    }

    return 0;
}

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

string S,T;
int x[10000],y[10000];
int dp[10000][10000];
char U[5]="abcd";
int MAXN;

int main(){
	int q;
	cin>>q;
	for(int i=0;i<q;i++){
		MAXN=0;
		cin>>S>>T;
		for(int i=0;i<S.size();i++){
			for(int j=0;j<4;j++){
				if(S[i]==U[j]){
					x[i+1]=j;
				}
			}
		}
		for(int i=0;i<T.size();i++){
			for(int j=0;j<4;j++){
				if(T[i]==U[j]){
					y[i+1]=j;
				}
			}
		}
		for(int i=0;i<=T.size();i++){
			for(int j=0;j<=S.size();j++){
				if(i==0 || j==0){
					dp[i][j]=0;
				}
				else if(x[j]==y[i]){
					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<=T.size();i++){
			for(int j=0;j<=S.size();j++){
				MAXN=max(MAXN,dp[i][j]);
			}
		}
		cout<<MAXN<<endl;
	}
	return 0;
}

C++: #include <cstdio>
#include <cmath>
#define MAX 1001
using namespace std;

int Lcc(const char *X, const char *Y) {
    int lcc = 0;
    int dp[MAX][MAX];
    for (int i=0; i<MAX; i++)
        for (int j=0; j<MAX; j++) dp[i][j] = 0;

    int x=0, y=0;
    for (int i=0;;i++) {
        if (X[i] == ',') {x = i;break;}
        for (int j=0;;j++) {
            if (Y[j] == ',') {
                y = j;
                break;
            } else {
                if (X[i] == Y[j]) {
                    dp[i+1][j+1] = fmax(dp[i][j] + 1, dp[i+1][j]);
                } else {
                    dp[i+1][j+1] = fmax(dp[i+1][j], dp[i][j+1]);
                }
            }
        }
    }
    return dp[x-1][y-1];
}

int
main()
{
    int q;
    scanf("%d", &q);
    for (int i=0; i<(q); i++) {
        char X[MAX], Y[MAX];
        for (int i=0; i<MAX; i++) {
            X[i] = ','; Y[i] = ',';
        }
        scanf(" %s", X);scanf(" %s", Y);
        int LCC = Lcc(X, Y);
        printf("%d\n", LCC);
    }
    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;
  c[0][0] = 0;
  for ( int i = 1; 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]);
    }
  }javascript:void(0)

  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;
}