Go: package main

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

type Position struct {
	X int
	Y int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}
	for i := 0; i < n; i++ {
		strX := nextText(sc)
		strY := nextText(sc)
		fmt.Println(calcLcs(strX, strY))
	}
}

func calcLcs(strX, strY string) int {
	return lcs(strX, strY, Position{0, 0}, make(map[Position]int))
}

func lcs(strX string, strY string, position Position, memo map[Position]int) int {
	if position.X >= len(strX) || position.Y >= len(strY) {
		return 0
	}
	if v, ok := memo[position]; ok {
		return v
	}
	if strX[position.X] == strY[position.Y] {
		result := lcs(strX, strY, Position{position.X + 1, position.Y + 1}, memo)
		memo[position] = result + 1
		return memo[position]
	} else {
		result1 := lcs(strX, strY, Position{position.X + 1, position.Y}, memo)
		result2 := lcs(strX, strY, Position{position.X, position.Y + 1}, memo)
		var result int
		if result1 > result2 {
			result = result1
		} else {
			result = result2
		}
		memo[position] = result
		return result
	}
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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

int lcs(string X, string Y) {
	int dp[1000 + 1][1000 + 1];
	int max = 0;

	for (int i = 0; i < X.length(); i++)
		dp[i][0] = 0;

	for (int i = 0; i < Y.length(); i++)
		dp[0][i] = 0;

	for (int i = 1; i < X.length(); i++) {
		for (int j = 1; j < Y.length(); j++) {
			if (X[i] == Y[i])
				dp[i][j] = dp[i - 1][j - 1] + 1;
			else if (dp[i - 1][j] >= dp[i][j - 1])
				dp[i][j] = dp[i - 1][j];
			else
				dp[i][j] = dp[i][j - 1];
			max = (max < dp[i][j]) ? dp[i][j] : max;
		}
	}

	return max;
}

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

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

		cout << lcs(X, Y) << endl;
	}

  return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;
string a,b;
int la,lb;
int dp[10000][10000];

void dpf(void){
	for(int i=1;i<=la;i++){
		for(int j=1;j<=lb;j++){
			if(a[i]==b[j]){
				dp[i][j]=dp[i-1][j-1]+1;
			}
			else{
				dp[i][j]=max(dp[i-1][j],dp[i][j-1]);
			}
		}
	}	
	return ;
}
int n;

int main(void){
	cin>>n;
	
	
for(int i=0;i<n;i++){	
	cin>>a>>b;
	la=a.length();
	lb=b.length();
	a=' '+a;
	b=' '+b;
	dpf();
	cout<<dp[la][lb]<<endl;
}


}

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

int main() {
  std::string X;
  std::string Y;
  int q;
  int answers[160];
  std::cin >> q;
  
  for(int p=0; p<q; ++p) {
    std::cin >> X;
    std::cin >> Y;

    int j=0;
    int c=0;

    for(int i=0; i<X.size(); ++i) {
      for(int k=j; k<=i; ++k) {
        if(k >= Y.size()) {
          break;
        }
        if(X[i] == Y[k]) {
          c++;
          j = k+1;
          break;
        }
      }
    }

    answers[p] = c;
  }

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

}

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

int lcs(string x,string y);

int main(){
	int n; cin>>n;
	string x,y;
	for(int i=0;i<n;i++){
		cin>>x>>y;
		cout<<lcs(x,y)<<endl;
	}
}

int lcs(string x,string y){
	int m = x.size() , n = y.size();
	x = ' '+x; y = ' '+y;
	int **c;
	c = new int*[m+1]; for(int i=0;i<=m;i++) c[i] = new int[n+1];
	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]);
			if(i==m&&j==n) return c[i][j];
		}
	}

	for(int i=0;i<=m;i++) delete [] c[i]; delete [] c;
}

C++: #include <cstdio>
#include <cstring>
#include <vector>
#include <set>
#include <map>
#include <algorithm>

using namespace std;

const int kMax = 1000 + 10;

int n, m;
char a_str[kMax], b_str[kMax];
int dp[kMax];

vector<int> init_num() {
    vector<int> res;
    map<char, set<int> > table;
    for(int i = 0;i < n;++ i) {
        if(table.count(a_str[i]) > 0) table[a_str[i]].insert(i);
        else {
            set<int> s;
            s.insert(i);
            table[a_str[i]] = s;
        }
    }
    for(int i = 0;i < m;++ i) {
        if(table.count(b_str[i]) > 0) {
            for(auto it = table[b_str[i]].rbegin();it != table[b_str[i]].rend();++ it) {
                res.push_back(*it);
            }
        }
    }
    return res;
}

int solve() {
    int res = 1;
    n = strlen(a_str);
    m = strlen(b_str);
    vector<int> num = init_num();
    dp[0] = num[0];
    for(int i = 1;i < num.size();++ i) {
        if(dp[res - 1] < num[i]) dp[res ++] = num[i];
        else dp[lower_bound(dp, dp + res, num[i]) - dp] = num[i];
    }
    return res;
}

int main() {
    int q;
    scanf("%d", &q);
    while(q --) {
        scanf("%s%s", a_str, b_str);
        printf("%d\n", solve());
    }
    return 0;
}

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

#define REP(i, n) for(int i=0;i<(int)(n);i++)
#define ALL(x) (x).begin(),(x).end()
const int INF = 1e9;

using namespace std;
int dp[1000][1001] = {0};

void dfs(int i, int j, string q, string b){
    int x = j;
    string tar = b.substr(x, 1);
    while(x < b.length() && q != tar){
        x++;
        tar = b.substr(x, 1);
    }
    if(i == 0 && x < b.length()){
        while(x < b.length()){
            x++;
            dp[i][x] = 1;
        }
        return;
    }
    while(x < b.length()){
        x++;
        dp[i][x] = max(dp[i-1][j] + 1, dp[i][x]);
    }
    dp[i][j] = max(dp[i][j], dp[i-1][j]);
    return;
}

int main() {
    int n; cin >> n;
    REP(k, n){
        string a, b;
        cin >> a >> b;
        REP(i, a.length()){
            string q = a.substr(i, 1);
            REP(j, b.length()+1) dfs(i, j, q, b);
        }
        cout << dp[a.length()-1][b.length()] << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> P;
typedef pair<ll, ll> Pll;
#define debug(var)  do{std::cout << #var << " : ";view(var);}while(0)
template<typename T> void view(T e){std::cout << e << std::endl;}
template<typename T> void view(const std::vector<T>& v){for(const auto& e : v){ std::cout << e << " "; } std::cout << std::endl;}
template<typename T> void view(const std::vector<std::vector<T> >& vv){ for(const auto& v : vv){ view(v); } }
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

const int MOD = 1000000007;
const int INF = 1e9;

const int mod = 1000000007;
const int inf = 1e9;
#define PI acos(-1);
int dx[4] = {1,-1,0,0};
int dy[4] = {0,0,1,-1};
int ddx[8] = {1,1,1,-1,-1,-1,0,0};
int ddy[8] = {0,1,-1,0,1,-1,1,-1};

void solve() {
    string s, t;
    cin >> s >> t;
    int sl = s.size(), tl = t.size();
    int dp[sl+1][tl+1];
    for(int i = 0; i < sl+1; i++) for(int j = 0; j < tl+1; j++) dp[i][j] = 0;
    for(int i = 0; i < sl; i++){
        for(int j = 0; j < tl; j++) {
            if(s[i] == t[j]) dp[i+1][j+1] = dp[i][j] + 1;
            chmax(dp[i+1][j+1], dp[i][j+1]);
            chmax(dp[i+1][j+1], dp[i+1][j]);
        }
    }
    cout << dp[sl][tl] << endl;
}

int main(){
    int t;
    cin >> t;
    while(t--) solve();
}