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 <bits/stdc++.h>

using ll = long long;
using namespace std;
constexpr ll inf = 1e15;
constexpr ll mod = 1e9+7;

ll dp[1001][1001] = {0};

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

    int Q;
    cin>>Q;
    for (int q = 0; q < Q; q++) {
        string X, Y;
        cin>>X>>Y;

        for (int i = 1; i <= X.length(); i++) {
            for (int j = 1; j <= Y.length(); j++) {
                dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
                if (X[i-1] == Y[j-1]) dp[i][j] = max(dp[i][j], dp[i-1][j-1]+1);
            }
        }
        cout<<dp[X.length()][Y.length()]<<endl;
    }
    return 0;
}

C++: #include<iostream>
#include<string>
#include<algorithm>
using namespace std;
#define MAX 1100

int temp[MAX][MAX];
int main(){
	int q;
	string x, y;
	
	cin>>q;
	
	for(int i = 1; i <= q; i++){
		cin>>x>>y;
		int sx = x.size() ,sy = y.size();
		for(int j = 0; j <= sx; j++)for(int k = 0; k <= sy; k++)temp[j][k] = 0;
		for(int j = 0; j < sx; j++){
			for(int k = 0; k < sy; k++){
				if(x[j] == y[k]){
					temp[j+1][k+1] = max(temp[j][k]+1,temp[j+1][k+1]);
				} else temp[j+1][k+1] = max(temp[j+1][k],temp[j][k+1]);
			}
		}
		cout<<temp[sx][sy]<<endl;
	}
	
	return 0;
}

C++: #include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <string>
#include <sstream>
#include <algorithm>
#include <iomanip>
#include <iostream>

#define VARIABLE(x) cerr << #x << "=" << x << endl
#define BINARY(x) static_cast<bitset<16> >(x);
#define if_range(x, w, h) if (w <= x && x <= h)
#define BitCheck(a,b)   (a >> b) & 1
#define BitSet(a,b)       a |= (1 << b)
#define BitunSet(a,b)    a &= ~(1 << b)

int compare_int(const void* a, const void* b) { return *(int*) a - *(int*) b; }

int main() {
	int n, m, a, dp[102][102] = { 0 };
	char s[1001], t[1001];
	scanf("%d", &a);
	for (int k = 0; a > k; k++) {
		scanf("%d %d %s %s", &n, &m, s, t);
		for (int i = 1; n >= i; i++) {
			for (int j = 1; m >= j; j++) {
				if (s[i - 1] == t[j - 1])dp[i][j] = dp[i - 1][j - 1] + 1;
				else dp[i][j] = __max(dp[i - 1][j], dp[i][j - 1]);
			}
		}
		printf("%d\n", dp[n][m]);
	}
	return 0;
}

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

void LCS(string X, string Y){
    X = ' ' + X; //＋演算子でX[0]に空白を挿入
    Y = ' ' + Y;
    int C[X.length()][Y.length()];
    
    for (int i = 0; i < X.length(); i++){
        C[i][0] = 0;
    }
    for (int i = 0; i < Y.length(); i++){
        C[0][i] = 0;
    }
    
    for (int i = 1; i < X.length(); i++){
        for (int j = 1; j < Y.length(); 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]);
        }
    }
    cout << C[X.length()-1][Y.length()-1] << endl;
    
}

int main(){
    int n;
    string X, Y;
    cin >> n;
    
    for (int 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 = 0; i <= m; i++)c[i][0] = 0;
	for (int j = 0; 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>
using namespace std;

#define REP(i, n) for(int (i) = 0; (i) < (n); (i)++)

string str1, str2;
int dp[1001][1001];
int k;

int solve(int i, int j)
{
  if(dp[i][j] >= 0)
    return dp[i][j];
  if(i >= str1.size() || j >= str2.size()){
    if(i < str1.size()){
      dp[i][j - 1] = 0;
      return solve(i + 1, k);
    }else{
      return 0;
    }
  }
  if(str1[i] == str2[j]){
    k = j + 1;
    int n, m = 0;
    for(int l = i + 1; l < str1.size(); l++){
      n = solve(l, j + 1);
      m = (n > m) ? n : m;
    }
    dp[i][j] = m + 1;
    return dp[i][j];
  }else{
    return solve(i, j + 1);
  }
}
  
int main()
{
  int q, n, m, ans = 0;
  cin >> q;
  cin.ignore();
  REP(i, q){
    getline(cin, str1);
    getline(cin, str2);
    if(str1.size() < str2.size())
      swap(str1, str2);
    fill(&dp[0][0], &dp[1001][0], -1);
    REP(j, str1.size()){
      n = solve(j, 0);
      ans = (n > ans) ? n : ans;
    }
    cout << ans << endl;
    ans = 0;
  }
}

C++: #include <iostream>
#include <string>
#include <algorithm>
using namespace std;
#define N 1000

int lcs(string X,string Y){
	int c[1001][1001];
	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;
}