Go: package main

/*
最長共通部分列
*/

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"os"
	"strconv"
	"strings"
)

func larger(l, r int) int {
	if l > r {
		return l
	}
	return r
}

var memo [1001][1001]int

func countLCS(x, y string) int {
	x = " " + x
	y = " " + y
	max := 0
	for xi := 1; xi < len(x); xi++ {
		for yi := 1; yi < len(y); yi++ {
			if x[xi] == y[yi] {
				memo[xi][yi] = memo[xi-1][yi-1] + 1
			} else {
				memo[xi][yi] = larger(memo[xi-1][yi], memo[xi][yi-1])
			}
			max = larger(max, memo[xi][yi])
		}
	}
	return max
}

func main() {
	scanner := makeScanner(1024)
	q := eGetInt(scanner)
	for i := 0; i < q; i++ {
		x := eGetLine(scanner)
		y := eGetLine(scanner)
		fmt.Println(countLCS(x, y))
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

type ints []int

func (s ints) String() string {
	var buf bytes.Buffer
	buf.WriteString("[")
	sep := ""
	for _, v := range s {
		buf.WriteString(fmt.Sprintf("%s%d", sep, v))
		sep = ", "
	}
	buf.WriteString("]")
	return buf.String()
}

func reverse(a ints) ints {
	r := make(ints, len(a))
	for i := 0; i < len(a); i++ {
		r[i] = a[len(a)-1-i]
	}
	return r
}
func max(a ints) (int, bool) {
	if len(a) == 0 {
		return 0, false
	}
	m := a[0]
	for _, e := range a {
		if e > m {
			m = e
		}
	}
	return m, true
}
func min(a []int) int {
	m := a[0]
	for _, v := range a {
		if v < m {
			m = v
		}
	}
	return m
}

func sum(a ints) int {
	if len(a) == 0 {
		return 0
	}
	sum := 0
	for _, e := range a {
		sum += e
	}
	return sum
}
func find(n int, a ints) int {
	for i, v := range a {
		if n == v {
			return i
		}
	}
	return -1
}

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 q;
  cin >> q;

  for ( int i = 0; i < q; 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;
    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 >> s2;
        cout << lcs(s1, s2) << endl;
    }
    
    return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <string>
#include <cctype>
#include <stack>
#include <queue>
#include <vector>
#include <cstdlib>

using namespace std;


int main(void) {

	char X[100], Y[100];
	char *S;
	int q;

	cin >> q;

	for (int i = 0;i < q;i++) {
		cin >> X;
		cin >> Y;
		S = strstr(X, Y);
		cout << strlen(S) << endl;
	}
		return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

#define Vi vector<int>
#define FOR(i,s,e) for (int i=s; i<e; i++)
#define ITER(v) v.begin(), v.end()

constexpr int MAX_LEN = 1'000;
int dp[MAX_LEN][MAX_LEN];

void set_val(int i, int j, int inc) {
    int val = inc;
    if (i > 0 && j > 0) {
        int tmp = dp[i-1][j-1] + inc;
        val = max(val, tmp);
    }
    if (i > 0) {
        int tmp = dp[i-1][j];
        val = max(val, tmp);
    }
    if (j > 0) {
        int tmp = dp[i][j-1];
        val = max(val, tmp);
    }
    dp[i][j] = val;
    //cout << i << " " << j << " " << val << endl;
}

int lcs(const string& x, const string& y) {
    int lx = x.length();
    int ly = y.length();
    for (int i=0; i<lx; ++i) {
        for (int j=0; j<ly; ++j) {
            if (x[i] == y[j]) {
                set_val(i, j, 1);
            } else {
                set_val(i, j, 0);
            }
        }
    }
    return dp[lx-1][ly-1];
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    string x, y;
    FOR(i,0,n) {
        cin >> x;
        cin >> y;
        cout << lcs(x, y) << endl;
    }

    return 0;
}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<cstdlib>
#include <cmath>
#include<stdio.h>
#include<queue>
#define MAX 1000000000000000000LL
long long inf=1000000007;
using namespace std;

int lcs(string X,string Y){
    int  c[1001][1001];
    long long m=X.size();
    long long 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 <cstdio>
#include <iostream>
#include <string>
#include <vector>

using namespace std;

#define pb push_back

typedef vector<int> vi;
typedef vector<vector<int> > vvi;

int lcs(string a, string b) {
  vvi len(a.length()+1, vi(b.length()+1, 0));
  for (int ia = 1 ; ia <= a.length() ; ia++) {
    for (int ib = 1 ; ib <= b.length() ; ib++) {
      if (a[ia-1] == b[ib-1]) {
        len[ia][ib] = len[ia-1][ib-1]+1;
      } else {
        len[ia][ib] = max(len[ia][ib-1], len[ia-1][ib]);
      }
    }
  }
  return len[a.length()][b.length()];
}

int main() {
  int t;
  cin >> t;
  vi results;
  for (int dataset = 0 ; dataset < t ; dataset++) {
    string a, b;
    cin >> a;
    cin >> b;
    results.pb(lcs(a, b));
  }

  for (int it = 0 ; it < t ; it++) {
    printf("%d\n", results[it]);
  }

  return 0;
}