Go: package main

import (
	. "fmt"
    "math"
)

// func init() { Println("----------------------------------------") }

func main() {
    const L_MAX = 1003

	var q int
	Scanf("%d", &q)
	X := make([]string, 0, 150)
	Y := make([]string, 0, 150)
	for i := 0; i < 2 * q; i++ {
	    var tmp string
	    Scanf("%s", &tmp)

	    if i % 2 == 0 {
	        X = append(X, tmp)
	    } else {
	        Y = append(Y, tmp)
	    }
	}

    for i := 0; i < q; i++ {
        dp := make([][]int, L_MAX)
        for k, _ := range dp {
            dp[k] = make([]int, L_MAX)
        }

        x, y := X[i], Y[i]

        // init
        isXFound := false
        for c := 0; c < len(x); c++ {
            if isXFound || y[0] == x[c] {
                dp[0][c] = 1
                isXFound = true
            }
        }
        isYFound := false
        for r := 0; r < len(y); r++ {
            if isYFound || x[0] == y[r] {
                dp[r][0] = 1
                isYFound = true
            }
        }

        for r := 1; r < len(y); r++ {
            for c := 1; c < len(x); c++ {
                // dp[r][c]
                if x[c] == y[r] {
                    dp[r][c] = int(math.Max(float64(dp[r - 1][c - 1] + 1), float64(dp[r][c])))
                }

                dp[r][c] = int(math.Max(float64(dp[r][c]), math.Max(float64(dp[r - 1][c]), float64(dp[r][c - 1]))))
            }
        }
        Println(dp[len(y) - 1][len(x) - 1])

        // LCSも求めておく
        // ans := ""
        // r, c := len(y) - 1, len(x) - 1
        // for r >= 0 && c >= 0 {
        //     if y[r] == x[c] {
        //         ans = string(x[c]) + ans
        //         r--
        //         c--
        //     } else {
        //         if dp[r - 1][c] > dp[r][c - 1] {
        //             r--
        //         } else {
        //             c--
        //         }
        //     }
        // }
        // Println(ans)
    }
}

C++: #include<algorithm>
#include<bitset>
#include<iostream>
#include<iomanip>
#include<set>
#include<string>
#include<math.h>
#include<string>
#include<queue>
#include<vector>
using namespace std;
typedef long long int ll;
typedef pair<int, ll> P;

//--------------
//#define DEBUG
//--------------

#ifdef DEBUG
	#define debugprint(x) cout<<x<<" "
	#define debugendl cout<<endl
	#define debug(x) x
#else
	#define debugprint(x)
	#define debugendl
	#define debug(x)
#endif

class zahyo{
	public:
	int x;
	int y;
	zahyo(){
		x=0;
		y=0;
	}
	zahyo(int x_,int y_){
		x=x_;
		y=y_;
	}
	void print(){
		cout<<x<<" "<<y;
	}
	zahyo operator+(zahyo add){
		add.x=this->x+add.x;
		add.y=this->y+add.y;
		return add;
	}
	zahyo operator-(zahyo add){
		add.x=this->x-add.x;
		add.y=this->y-add.y;
		return add;
	}
	zahyo operator*(int t){
		zahyo temp;
		temp.x=this->x*t;
		temp.y=this->y*t;
		return temp;
	}
	zahyo operator%(int t){
		zahyo temp(this->x%t,this->y%t);
		return temp;
	}
	zahyo operator/(int t){
		zahyo temp(this->x/t,this->y/t);
		return temp;
	}
	bool operator==(const zahyo add) const{
		if(add.x==this->x and add.y==this->y){return true;}
		else{return false;}
	}
	bool operator!=(const zahyo add) const{
		if(add.x==this->x or add.y==this->y){return false;}
		else{return true;}
	}
	bool operator<(const zahyo add) const{
		if(this->x<add.x){return true;}
		else if(this->x==add.x and this->y<add.y){return true;}
		else{return false;}
	}
	bool operator>(const zahyo add) const{
		if(this->x>add.x){return true;}
		else if(this->x==add.x and this->y>add.y){return true;}
		else{return false;}
	}
	void input(){
		cin>>x>>y;
	}
};

bool IsInBoard(int x,int maxx, int y,int maxy){
	if(x>=0 and x<maxx and y>=0 and y<maxy){
		return true;
	}
	else{
		return false;
	}
}

int main(){
	int q;
	cin>>q;
	for(int i=0;i<q;i++){
		string x,y;
		cin>>x>>y;
		int dp[1001][1001]={};
		for(int j=1;j<=x.size();j++){
			for(int k=1;k<=y.size();k++){
				int same=0;
				if(x[j-1]==y[k-1]){
					same=1;
				}
				dp[j][k]=max(dp[j-1][k-1]+same,max(dp[j-1][k],dp[j][k-1]));
			}
		}
		cout<<dp[x.size()][y.size()]<<endl;
	}

}

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 <algorithm>
#include <iostream>
#include <string>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <deque>
#include <iomanip>
#include <limits>
#include <map>
#include <queue>
#include <stack>
#include <vector>

#define FOR(i,k,n) for(int (i) = (k); (i) < (n); ++(i))
#define rep(i,n) FOR(i,0,n)
#define pb push_back
#define all(v) begin(v), end(v)
#define debug(x) cerr << #x << ": " << x << endl
#define debug2(x,y) cerr << #x << ": " << x << ", " << #y << ": " << y << endl

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<i_i, int> p_i;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
template<class T> using vv=vector<vector<T>>;
typedef deque<int> di;
typedef deque<deque<int>> ddi;


int main() {
    int q;
    cin >> q;
    rep(i,q) {
        string x,y;
        cin >> x >> y;
        int dp[1050][1050] = {};
        rep(i,(int)x.length()) {
            rep(j,(int)y.length()) {
                if(i == 0 && j == 0) {
                    if(x[i] == y[j]) {
                        dp[i][j] = 1;
                    } 
                } else if(i == 0) {
                    if(x[i] == y[j]) {
                        dp[i][j] = 1;
                    } else { 
                        dp[i][j] = dp[i][j-1];
                    }
                } else if(j == 0) {
                    if(x[i] == y[j]) {
                        dp[i][j] = 1;
                    } else { 
                        dp[i][j] = dp[i-1][j];
                    }
                } else if(x[i] == y[j]) {
                    dp[i][j] = dp[i-1][j-1] +1;
                } else {
                    dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
                }
            }
        }
        cout << dp[x.length()-1][y.length()-1] << endl;
    }
	return 0;
}

C++: // input: alds1_10_c.in
#include<iostream>
#include<algorithm>
#define MAX_X 1000
#define MAX_Y 1000
using namespace std;

int c[MAX_X+1][MAX_Y+1];

int lcs(string& a, string& b) {
  a = ' ' + a;
  b = ' ' + b;

  for(int i=0; i<a.length(); i++) {
    c[i][0] = 0;
  }
  for(int i=0; i<b.length(); i++) {
    c[0][i] = 0;
  }

  for(int i=1; i<a.length(); i++) {
    for(int j=1; j<b.length(); j++) {
      if(a[i] == b[j]) {
        c[i][j] = c[i-1][j-1] + 1;
      } else {
        c[i][j] = max(c[i][j-1], c[i-1][j]);
      }
    }
  }

  return c[a.length()-1][b.length()-1];
}

int main() {
  int n;
  string a, b;
  cin >> n;
  for(int i=0; i<n; i++) {
    cin >> a >> b;

    cout << lcs(a, b) << endl;
  }
}

C++: #include <iostream>
#include <algorithm>
#include <string>
using namespace std;
const int MAX=1001;
int lcs(string X,string Y) 
{
	int i=0,j=0,c[MAX][MAX],x=X.length(),y=Y.length();
	for(i=0;i<=x;i++)c[i][0]=0;
	for(i=0;i<=y;i++)c[0][i]=0;
	for(i=1;i<=x;i++) 
	for(j=1;j<=y;j++) 
	if(X[i-1]==Y[j-1])c[i][j]=c[i-1][j-1]+1; 
	else if(c[i-1][j]>c[i][j-1])c[i][j]=c[i-1][j];
	else c[i][j]=c[i][j-1];
	return c[x][y];
}
int main()
{
	int n;cin>>n;
	string X,Y;
	while(n--)
	{
		cin>>X>>Y;
		cout<<lcs(X,Y)<<endl;
	}
}