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 <stdio.h>

int judge(char A[], char B[]){
  int a=0, b=0, sw=0, ans=0;
  int i, j;
  int C[1001][1001];
  
  while(sw == 0){
    if(A[a] != '\0')
      a++;
    else
      sw = 1;
  }
  
  sw = 0;
  
  while(sw == 0){
    if(B[b] != '\0')
      b++;
    else
      sw = 1;
  }
  
  for(i=1; i<a+1; i++)
    C[i][0] = 0;
  for(i=1; i<b+1; i++)
    C[0][i] = 0;
  
  for(i=1; i<a+1; i++){
    for(j=1; j<b+1; j++){
      if(A[i-1] == B[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];
      if(ans < C[i][j])
        ans = C[i][j];
    }
  }
  
  return ans;
}

int main(){
  char A[1000], B[1000];
  int n, i;
  
  scanf("%d", &n);
  
  for(i=0; i<n; i++){
    scanf("%s", A);
    scanf("%s", B);
    printf("%d\n", judge(A, B));
  }
  
  return 0;
}

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

int Longest(string x, string y) {
  int L[1001][1001];
  int maxl = -1;
  int xlen = x.size();
  int ylen = y.size();

  x = ' ' + x;
  y = ' ' + y;

  for (int i = 1; i <= xlen; i++) L[i][0] = 0;
  for (int j = 1; j <= ylen; j++) L[0][j] = 0;

  for (int i = 1; i <= xlen; i++) {
    for (int j = 1; j <= ylen; j++) {
      if (x[i] == y[j])
        L[i][j] = L[i-1][j-1] + 1;
      else
        L[i][j] = max(L[i][j-1], L[i-1][j]);

      maxl = max(maxl, L[i][j]);
    }
  }

  return maxl;
}

int main() {
  string X, Y;
  int n;
  int result[1001];

  cin >> n;

  for (int i = 0; i < n; i++) {
    cin >> X;
    cin >> Y;
    result[i] =  Longest(X, Y);
    cout << result[i] << endl;
  }




  return 0;
}

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

#define MAX 10000

using namespace std;

int lcs(string s1, string s2) {
    int C[MAX+1][MAX+1];
    int m = s1.size();
    int n = s2.size();
    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 (s1[i-1] == s2[j-1]) {
                C[i][j] = C[i-1][j-1] + 1;
            }
            else {
                C[i][j] = max(C[i][j-1], C[i-1][j]);
            }
        }
    }

    return C[m][n];
}

int main() {
    int n;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        string s1, s2;
        cin >> s1 >> s2;
        cout << lcs(s1, s2) << endl;
    }
    return 0;
}

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

struct info {
	int max{};
	bool done{};
};

int build_dp(info[1000][1000], int, int);
std::string str_x, str_y;

int main()
{
	int q;

	std::cin >> q;
	for (int i = 0; i < q; ++i)
	{
		info dp[1000][1000] {};
		std::cin >> str_x >> str_y;
		std::cout << build_dp(dp, str_x.size() - 1, str_y.size() - 1) << std::endl;
	}
	return 0;
}

int build_dp(info dp[1000][1000], int x_i, int y_i)
{
	if (x_i < 0 || y_i < 0) return 0;
	if (dp[x_i][y_i].done == true) return dp[x_i][y_i].max;

	if (str_x[x_i] == str_y[y_i])
	{
		dp[x_i][y_i].max = build_dp(dp, x_i - 1, y_i - 1) + 1;
		dp[x_i][y_i].done = true;
	}
	else
	{
		dp[x_i][y_i].max = std::max(build_dp(dp, x_i - 1, y_i), build_dp(dp, x_i, y_i - 1));
		dp[x_i][y_i].done = true;
	}
	return dp[x_i][y_i].max;
}

C++: #include <iostream>

using namespace std;

int ans(string a, string b) {
  int n = a.size();
  int m = b.size();
  int memo[n+1][m+1];
  for (int i = 0; i <= n; i++) {
    for (int j = 0; j <= m; j++) {
      memo[i][j] = 0;
    }
  }

  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      int res = max(memo[i-1][j], memo[i][j-1]);
      if (a[i-1] == b[j-1]) {
        res = max(res, memo[i-1][j-1] + 1);
      } else {
        res = max(res, memo[i-1][j-1]);
      }
      memo[i][j] = res;
    }
  }
  
  return memo[n][m];
}

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

  for (int i = 0; i < q; i++) {
    string a, b;
    cin >> a >> b;
    
    cout << ans(a, b) << endl;
  }

  return 0;
}

C++: #include<iostream>

using namespace std;

int dp[1001][1001];

int main(){
    int q, m, n;
    cin >> q;

    while(q-- > 0){
        string x, y;
        cin >> x >> y;
        m = x.length();
        n = y.length();
        for(int i = 0; i <= m; i++) dp[i][0];
        for(int i = 0; i <= n; i++) dp[0][i];

        for(int i = 1; i <= m; i++){
            for(int j = 1; j <= n; j++){
                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[m][n] << 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 = 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;
}