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>
usig 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++){
    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<bits/stdc++.h>
using namespace std;
#define inf 1e9
#define ll long long
#define ull unsigned long long
#define M 1000000007
#define P pair<int,int>
#define PLL pair<ll,ll>
#define FOR(i,m,n) for(int i=(int)m;i<(int)n;i++)
#define RFOR(i,m,n) for(int i=(int)m;i>=(int)n;i--)
#define rep(i,n) FOR(i,0,n)
#define rrep(i,n) RFOR(i,n,0)
#define all(a) a.begin(),a.end()
#define IN(n,a) rep(i,n){ cin>>a[i]; }
const int vx[4] = {0,1,0,-1};
const int vy[4] = {1,0,-1,0};
#define PI 3.14159265


void f(){
  string x,y;
  cin>>x>>y;
  int dp[1100][1100]={};
  
  rep(i,x.length()+1){
    rep(j,y.length()+1){
      if(i==0||j==0) continue;
      if(x[i-1]==y[j-1]) dp[i][j]=dp[i-1][j-1]+1;
      else dp[i][j]=max(dp[i-1][j],dp[i][j-1]);
        }
      }
    }
  }

  cout<<dp[(int)x.length()][(int)y.length()]<<endl;
}


int main(){
  int q;
  cin>>q;
  while(q--){
    f();
  }
}

C++: #include <iostream>
#include <string>
using namespace std;
static const int MAX = 1001;

void lcs(string X, string Y) {
	int dp[MAX][MAX];  
	int i,j;

	int xLength = X.size();
	int yLength = Y.size();


	// initialize dp[][]
	for (i = 1; i <= xLength; i++)
		dp[i][0] = 0;
	for (i = 1; i <= yLength; i++)
		dp[0][i] = 0;

	for (i = 1; i <= xLength; i++){
		for (j = 1; j <= yLength; j++){
			// Because the original string is 0-based , so subtracted from 1
			if (X[i - 1] == Y[j - 1]) {
				dp[i][j] = dp[i-1][j-1] + 1;
			}else {
				dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
			}
		}
	}

	// testing code: print out the dp[][]
	// cout << "j";
	// for (j = 1; j <= yLength; j++)
	// 	cout << ' ' << j ;
	// cout << endl;
		

	// for (i = 1; i <= xLength; i++){
	// 	cout << i << '.';
	// 	for (j = 1; j <= yLength; j++){
	// 		cout << dp[i][j] << ' ';
	// 	}
	// 	cout << endl;
	// }

	cout << dp[xLength][yLength] << endl;
}

int main() {
	int n , i;
	string X, Y;

	cin >> n;
	for (i = 0 ; i < n; i++ ) {
		cin >> X;
		cin >> Y;
		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 = 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] = mx(c[i - 1][j], c[i][j = 1]);
      }
      maxl = max(mxl, 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 << lcs8s1, s2) << endl;
  }
  return 0;
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <cmath>
#include <set>
#include <algorithm>
#include <array>
#include <complex>
#include <utility>
#include <map>
#include <inttypes.h>

int LCS(std::string s,std::string t){
    int n,m,c[1001][1001]={0};
    n=s.size();
    m=t.size();
    int maxlen=0;
    for(int i=1;i<=n;i++){
        c[i][0]=0; 
    }
    for(int i=1;i<=m;i++){
        c[0][i]=0;
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            if(s[i-1]==t[j-1]){
                c[i][j]=c[i-1][j-1]+1;
            }else{
                c[i][j]=std::max(c[i-1][j],c[i][j-1]);
            }
            maxlen=std::max(maxlen,c[i][j]);
        }
    }
    return maxlen;
}
int main(){
	int N;
    
    std::cin >> N;
    std::string s1,s2;
    for(int i=0;i<N;i++){
        std::cin >> s1 >> s2;
        std::cout << LCS(s1,s2) <<std::endl;
    }
    return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <string>
#include <vector>
#include <list>
#include <set>
#include <map>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define INT(a) int((a)+1e-9)
#define UNDEFCHAN -1
#define SUPL 1002
#define MISERU(name,value) cout<<name<<": "<<value<<endl;

int xl,yl;
char xs[SUPL],ys[SUPL];
int rss[SUPL][SUPL];

int r(int xi, int yi){
	if (rss[xi][yi]!=UNDEFCHAN) return rss[xi][yi];
	int re;
	if(xi==0) re=0;
	else if(yi==0) re=0;
	else if(xs[xi-1]==ys[yi-1]) re=r(xi-1,yi-1)+1;
	else re=max(r(xi-1,yi),r(xi,yi-1));
	rss[xi][yi]=re;
	return re;
}

int solve(){
	REP(xi,xl+1) REP(yi,yl+1) rss[xi][yi]=UNDEFCHAN;
	return r(xl,yl);
}

int main(){
	int ol;
	cin>>ol;
	REP(oi,ol){
		cin>>xs;
		cin>>ys;
		xl=strlen(xs);
		yl=strlen(ys);
		cout<<solve()<<endl;
	}
	return 0;
}

C++: #include<iostream>

using namespace std;

int max(int x, int y){
	return (x < y) ? y : x;
}

int get_lcs_len(char X[1000], char Y[1000]){
	int x_len=0, y_len=0;

	for(; 'a'<=X[x_len] && X[x_len]<='z'; x_len++);
	for(; 'a'<=Y[y_len] && Y[y_len]<='z'; y_len++);
	for(; 'A'<=X[x_len] && X[x_len]<='Z'; x_len++);
	for(; 'A'<=Y[y_len] && Y[y_len]<='Z'; y_len++);

	int dp[y_len+1][x_len+1]={};
	int result = 0;

	for(int i=1; i<=y_len; i++){
		for(int j=1; j<=x_len; j++){
			if(X[j-1] == Y[i-1]){
				dp[i][j] = dp[i-1][j-1] + 1;
			}else{
				dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
			}
			result = max(result, dp[i][j]);
		}
	}

	return result;
}

int main(){
	int q;
	char X[1000], Y[1000];

	cin >> q;

	int results[q];

	for(int i=0; i<q; i++){
		cin >> X >> Y;
		results[i] = get_lcs_len(X, Y);
	}

	for(int i=0; i<q; i++){
		cout << results[i] << endl;
	}

	return 0;
}