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 <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 a, b;

    cin >> N;

    for(i = 0 ; i < N ; i++) {
        cin >> a;
        cin >> b;
        cout << lcs(a, b) << endl;
    }

    return 0;
}

C++: /*
** Longest Common Subsequence
*/

# include <cstdio>
# include <cstring>
# include <algorithm>
using namespace std;

const int MAX = 1000 + 5;

char s1[MAX], s2[MAX];
int c[MAX][MAX];

int lcs() {
    int m = strlen(s1);
    int n = strlen(s2);
    c[0][0] = 0;
    int maxl = 0;
    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 = 0; i < m; i++) {
        for (int j = 0; j < n; j++) {
            if (s1[i] == s2[j]) {
                c[i][j] = c[i - 1][j - 1] + 1;
            }
            else {
                c[i][j] = max(c[i][j - 1], c[i - 1][j]);
            }
            maxl = max(maxl, c[i][j]);
        }
    }

    return maxl;
}

void solve() {
    int n;
    scanf("%d", &n);
    while (n--) {
        scanf("%s %s", s1, s2);
        printf("%d\n", lcs());
    }
}

int main() {
    // freopen("infile", "r", stdin);
    // freopen("outfile", "w", stdout);
    solve();
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

int main(void){
    int Q;
    cin >> Q;
    
    for(int q = 0;q < Q;q++){
        string x,y;
        cin >> x >> y;
        
        int dp[x.size()+1][y.size()+1];
        for(int i = 0;i < x.size()+1;i++){
            for(int j = 0;j < y.size()+1;j++){
                dp[i][j] = 0;
            }
        }
        
        for(int i = 0;i < x.size();i++){
            for(int j = 0;j < y.size();j++){
                if(x[i] == y[j]){
                    dp[i+1][j+1] = max(dp[i+1][j+1],dp[i][j]+1);
                }
                dp[i+1][j+1] = max(dp[i+1][j+1],dp[i][j+1]);
                dp[i+1][j+1] = max(dp[i+1][j+1],dp[i+1][j]);
            }
        }
        cout << dp[x.size()][y.size()] << endl;
    }
}

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

#define N 1000

int lcs(string x, string y) {
  int i, j, m, n, lcs[N+1][N+1];
  
  m = x.length();
  n = y.length();
  // indexずれを補正
  x = ' ' + x;
  y = ' ' + y;
  
  // 初期値
  for (i = 0; i < m + 1; i++) lcs[i][0] = 0;
  for (j = 0; j < n + 1; j++) lcs[0][j] = 0;
  // 漸化式
  for (i = 1; i <= m; i++) {
    for (j = 1; j <= n; j++) {
      if (x[i] == y[j]) lcs[i][j] = lcs[i-1][j-1] + 1;
      else lcs[i][j] = max(lcs[i-1][j], lcs[i][j-1]);
    }
  }

  return lcs[m][n];
}

int main() {
  int i, q, lcs_arr[N];
  string x, y;

  cin >> q;

  for (i = 0; i < q; i++) {
    cin >> x;
    cin >> y;
    lcs_arr[i] = lcs(x, y);
  }    

  for (i = 0; i < q; i++) cout << lcs_arr[i] << endl;
    
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <cstdlib>
#include <cstring>
#include <fstream>

#define SMAX 1000
#define QMAX 150

using namespace std;

int main()
{
  int q;
  cin >> q;
  
  char X[SMAX], Y[SMAX];
  int LCS[SMAX+1][SMAX+1] = {0};
  int Anwser[QMAX];
  for(int i = 0; i<q; i++) {
    scanf("%s",X);
    scanf("%s",Y);
    int size_X = strlen(X);
    int size_Y = strlen(Y);
    for(int j = 0; j <= size_X; j++) LCS[j][0] = 0;
    for(int j = 0; j <= size_Y; j++) LCS[0][j] = 0;

    for(int j = 1; j <= size_X; j++) {
      for(int k = 1; k <= size_Y; k++) {
	if(X[j-1] == Y[k-1]) LCS[j][k] = LCS[j-1][k-1] + 1;
	else LCS[j][k] = max(LCS[j-1][k], LCS[j][k-1]);
      }
    }
    Anwser[i] = LCS[size_X][size_Y];
  }

  for(int i = 0; i<q; i++) cout << Anwser[i] << endl;

  return 0;
}

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

static const int N = 100;

int main(){
	int n, p[N + 1], m[N + 1][N + 1];
	cin >> n;
	for(int i=1;i<=n;i++){
		cin >> p[i - 1] >> p[i];
	}

	for(int i=1;i<=n;i++) m[i][i] = 0;
	for(int l=2;l<=n;l++){
		for(int i=1;i<=n-l+1;i++){
			int j=i+l-1;
			m[i][j] = (1 << 21);
			for(int k=i;k<=j-1;k++){
				m[i][j] = min(m[i][j], m[i][k] + m[k+1][j] + p[i-1] * p[k] * p[j]);
			}
		}
	}

	cout << m[1][n] << endl;

	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=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;
}