Go: package main

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

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

func lcs(a, b string) int {
	lenA := len(a)
	lenB := len(b)
	dp := make([][]int, lenA+1)
	for i := range dp {
		dp[i] = make([]int, lenB+1)
	}

	for i := 1; i <= lenA; i++ {
		for j := 1; j <= lenB; j++ {
			if a[i-1] == b[j-1] {
				dp[i][j] = dp[i-1][j-1] + 1
			} else {
				dp[i][j] = max(dp[i][j-1], dp[i-1][j])
			}
		}
	}
	return dp[lenA][lenB]
}

func main() {
	n := scanInt()
	w := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		a := scanString()
		b := scanString()
		fmt.Fprintln(w, lcs(a, b))
	}
	w.Flush()
}

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;
		cin >> s2;
		cout << lcs(s1, s2) << endl;
	}
	return 0;
}

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

int main(){
  int n,b[1100][1100];
  string s1,s2;
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>s1>>s2;
    for(int j=0;j<=s1.size()+1;j++)b[j][0]=0;
    for(int j=0;j<=s2.size()+1;j++)b[0][j]=0;
    for(int j=1;j<=s1.size();j++){
      for(int k=1;k<=s2.size();k++){
	if(s1[j-1]==s2[k-1])b[j][k]=b[j-1][k-1]+1;
	else if(b[j][k-1]>b[j-1][k])b[j][k]=b[j][k-1];
	else b[j][k]=b[j-1][k];
      }
    }
    cout<<b[s1.size()][s2.size()]<<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;  // X[0] に空白を挿入
  Y = ' ' + Y;  // Y[0] に空白を挿入
  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 <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;//??¨X[0]????????\?????????
	Y=' '+Y;//??¨Y[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]);
		}
	}
	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 <string>

int max(int a, int b, int c);

int main(){
    int n;
    std::cin >> n;
    std::string str1;
    std::string str2;
    for(int i=0;i<n;i++){
        std::cin >> str1;
        std::cin >> str2;
        int size1 = str1.size();
        int size2 = str2.size();
        int dp[size1+1][size2+1];
        dp[0][0] = 0;
        for(int j=0;j<=size1;j++){
            dp[j][0] = 0;
        }
        for(int j=0;j<=size2;j++){
            dp[0][j] = 0;
        }

        for(int j=1;j<=size1;j++){
            for(int k=1;k<=size2;k++){
                dp[j][k] = max(dp[j-1][k],dp[j-1][k-1],dp[j][k-1]);
                if(str1[j]==str2[k]) dp[j][k]++;
            }
        }

        std::cout << dp[size1][size2] << std::endl;
    }
    return 0;
}

int max(int a, int b, int c){
    if(a>b){
        if(a>c){
            return a;
        }else{
            return c;
        }
    }else{
        if(b>c){
            return b;
        }else{
            return c;
        }
    }
}

C++: #include<stdio.h>
#include<string.h>

int main(){
  char X[1001],Y[1001];
  int i,j,n,x,y,k;
  int l[1001][1001];  
  scanf("%d",&n);
  
  for(k=0;k<n;k++){
    
    scanf("%s%s",X,Y);
    x=strlen(X);
    y=strlen(Y);
    
    for(i=0;i<=x;i++){
      for(j=0;j<=y;j++){
	l[i][j]=0;
      }	
    }
    
    for(i=1;i<=x;i++){
      for(j=1;j<=y;j++){
	if(X[i]==Y[j])  l[i][j]=l[i-1][j-1]+1;
	else if(l[i-1][j]>=l[i][j-1]) l[i][j]=l[i-1][j];
	else l[i][j]=l[i][j-1];
      }
    }
    printf("%d\n",l[i-1][j-1]);
    
  }
}

C++: #include<iostream>
#include<string>
#include<vector>

using namespace std;

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

int lcs(string x, string y) {
	int l1 = x.size(),l2 = y.size();
	vector<vector<int> > dp(l1 + 1, vector<int>(l2 + 1, 0));
	for (int i = 1;i <= l1;i++) {
		for (int j = 1;j <= l2;j++) {
			if (l1 == 0 || l2 == 0) {
				dp[i][j] = 0;
			}
			else 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]);
			}
		}
	}
	return dp[l1][l2];
}


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

	for (int i = 1;i <= n;i++) {
		string x, y;
		cin >> x;
		cin >> y;
		cout << lcs(x, y) << 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;
}

C++: #include <iostream>
#include <string>
#include <algorithm>

using namespace std;

static const int N = 1000;

static int lcs(string& s1, string& s2) {
    int table[N + 1][N + 1];

    int m = s1.size();
    int n = s2.size();

    int max_len = 0;

    s1 = ' ' + s1;
    s2 = ' ' + s2;

    for (int i = 0; i <= m; i++) table[i][0] = 0;
    for (int j = 0; j <= m; j++) table[0][j] = 0;

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

            max_len = max(table[i][j], max_len);
        }
    }

    return max_len;
}

int main() {
    int n;

    cin >> n;

    for (int i = 0; i < n; i++) {
        string s1, s2;

        cin >> s1 >> s2;

        cout << lcs(s1, s2) << endl;
    }

    return 0;
}