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

        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<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 <cstring>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <functional>
#include <vector>
#include <list>
#include <queue>
#include <deque>
#include <stack>
#include <map>
#include <set>
#include <bitset>
#include <tuple>
#include <cassert>
#include <exception>
#include <iomanip>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll> P;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<string> vs;
typedef vector<P> vp;
#define rep(i,a,n) for(ll i = (a);i < (n);i++)
#define per(i,a,n) for(ll i = (a);i > (n);i--)
#define lep(i,a,n) for(ll i = (a);i <= (n);i++)
#define pel(i,a,n) for(ll i = (a);i >= (n);i--)
#define clr(a,b) memset((a),(b),sizeof(a))
#define pb push_back
#define mp make_pair
#define all(c) (c).begin(),(c).end()
#define sz size()
#define print(X) cout << (X) << endl
#define fprint(NUM,X) cout << fixed << setprecision(NUM) << (X) << endl
#define fprints(NUM,X,Y) cout << fixed << setprecision(NUM) << (X) << " " << (Y) << endl
const ll INF = 1e+9+7;
ll n,m,l;
string s,t;
ll d[200010],dp[1000][1000];
double w[1000],v[1000];
double box[200010];

ll func(){
  ll ans = 0;
  rep(i,0,s.sz)dp[i][0] = 0;
  rep(i,0,t.sz)dp[0][i] = 0;
  rep(i,0,s.sz){
    rep(j,0,t.sz){
      if(s[i] == t[j]){
        dp[i+1][j+1] = dp[i][j] + 1;
      }else{
        dp[i+1][j+1] = max(dp[i+1][j] , dp[i][j+1]);
      }
    }
    ans = max(ans,dp[s.sz][t.sz]);
  }
  return ans;
}

int main(){
  cin >> n;
  rep(i,0,n){
    cin >> s >> t;
    print(func());
  }
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include<string.h>
using namespace std;
int LCS(char *x,char *y);
char x[1001], y[1001];
int lcs[1001][1001];
int main()
{
	int q,i,j;

	cin >> q;
	for (i = 0; i < q; i++) {
		cin >> x;
		cin >> y;
		cout << LCS(x, y) << endl;
	}
}

int LCS(char *x, char *y)
{
	int i, j;
	int len_x, len_y;
	len_x = strlen(x);
	len_y = strlen(y);
	for (i = 0; i < len_x; i++) {
		for (j = 0; j < len_y; j++) {
			lcs[i][j] = '\0';
		}
		//cout << endl;
	}
	for (i = 0; i < len_x; i++) {
		if (x[i] == y[0]) {
			lcs[i][0] = 1;
		}
		else {
			lcs[i][0] = 0;
		}
	}
	for (i = 0; i < len_y; i++) {
		if (x[0] == y[i]) {
			lcs[0][i] = 1;
		}
		else {
			lcs[0][i] = 0;
		}
	}

	for (i = 0; i < len_x; i++) {
		for (j = 0; j < len_y; j++) {
			if (x[i] == y[j]) {
				lcs[i][j] = lcs[i - 1][j - 1] + 1;
				//printf("lcs[%d][%d]=%d\n", i, j, lcs[i - 1][j - 1] + 1);
			}
			if (x[i] != y[j]) {
				lcs[i][j] = max(lcs[i - 1][j], lcs[i][j - 1]);
				//printf("lcs[%d][%d]=%d\n", i, j, max(lcs[i - 1][j], lcs[i][j - 1]));
			}
		}
	//cout << endl;

	}
	for (i = 0; i < len_x; i++) {
		for (j = 0; j < len_y; j++) {
			//printf("%d ", lcs[i][j]);
		}
		//cout << endl;
	}
	//cout << "len_x=" << len_x << endl << "len_y=" << len_y << endl;
			
	return lcs[i-1][j-1];
}

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

int lcs(string str1, string str2)
{
	int len[1001][1001] = { 0 };

	int len1 = str1.length();
	int len2 = str2.length();
	str1 = " " + str1;
	str2 = " " + str2;

	for (int i = 0; i <= len1; i++)
		for (int j = 0; j <= len2; j++) len[i][j] = 0;

	for (int i = 1; i <= len1; i++)
	{
		for (int j = 1; j <= len2; j++)
		{
			if (str1[i] == str2[j]) len[i][j] = len[i - 1][j - 1] + 1;
			else len[i][j] = max(len[i - 1][j], len[i][j - 1]);
		}
	}
	return len[len1][len2];
}

int main()
{
	int n;
	string str1, str2;

	cin >> n;
	for (int i = 0; i < n; i++)
	{
		cin >> str1 >> str2;
		cout << lcs(str1, str2) << endl;
	}

	return 0;
}

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

int main(){
    int q;
    std::string X,Y;
    std::cin>>q;

    int xy[1000][1000]={};
    
    for(int i=0;i<q;i++){
        std::cin>>X>>Y;
        //int xy[1001][1001]={};
        for(int j=1;j<=X.size();j++){
            for(int k=1;k<=Y.size();k++){
                if(X[j-1]==Y[k-1]){
                    xy[j][k]=xy[j-1][k-1]+1;
                }else{
                    xy[j][k]=std::max(xy[j][k-1],xy[j-1][k]);
                }
            }
        }
        std::cout<<xy[X.size()][Y.size()]<<"\n";
    }

return 0;
}