Go: package main

import (
	"fmt"
)

func main() {
	var q int
	fmt.Scan(&q)

	for i := 0; i < q; i++ {
		var x, y string
		fmt.Scan(&x)
		fmt.Scan(&y)

		xs := []rune(x)
		ys := []rune(y)

		xn := len(xs)
		yn := len(ys)
		dp := make([][]int, xn+1)
		for j := 0; j <= xn; j++ {
			dp[j] = make([]int, yn+1)
		}

		for j := 1; j <= xn; j++ {
			for k := 1; k <= yn; k++ {
				dp[j][k] = max(dp[j-1][k], dp[j][k-1])
				if xs[j-1] == ys[k-1] {
					dp[j][k] = max(dp[j][k], dp[j-1][k-1] + 1)
				} else {
					dp[j][k] = max(dp[j][k], dp[j-1][k-1])
				}
			}
		}
		fmt.Println(dp[xn][yn])
	}
}

func max(a, b int) int {
	if a < b {
		return b
	} else {
		return a
	}
}

C++: #include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int c[1010][1010];
int lcs(string x,string y){
    int m = x.size();
    int n = y.size();
    int maxl;
    for (int i=1; i<=m; i++) {
        c[i][0] = 0;
    }
    for(int j=1;j<=n;j++){
        c[0][j] = 0;
    }
    x = ' '+x;
    y = ' '+y;
    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(){
    int q;
    string x;
    string y;
    scanf("%d",&q);
    for (int i=0; i<q; i++) {
        cin>>x>>y;
        cout<<lcs(x, y)<<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();
	c[0][0] = 0;
	int maxl = 0;
	X = ' ' + X;
	Y = ' ' + Y;
	for (int i = 1; i <= m; i++) c[i][0] = 0;
	for (int i = 1; i <= n; i++) c[0][i] = 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()
{
	int n;
	string s1, s2;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> s1 >> s2;
		cout << lcs(s1, s2) << endl;
	}
    return 0;
}

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

static const int N = 1000;

int lcs(string X, string Y) {
    int c[N + 1][N + 1] = {};
    int m = X.length();
    int n = Y.length();

    X = ' ' + X;
    Y = ' ' + Y;
    
    int maxl = 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() {
    int n;
    string X, Y;
    cin >> n;

    for(int i = 0; i < n; i++) {
        cin >> X >> Y;
        lcs(X, Y);
    }
        
    return 0;
}

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

using namespace std;

string s1, s2;

int lcs() {
  int i, j, flag = 0;
  int dp[s1.length()+1][s2.length()+1] = {};
  
  for(i = 1; i <= s1.length(); i++) {
    for(j = 1; j <= s2.length(); j++) {
      dp[i][j] = max(max(dp[i-1][j-1], dp[i-1][j]), dp[i][j-1]);
      if(s1[i-1] == s2[j-1] && flag == 0) { 
	dp[i][j]++;
	flag++;
      }
      //      cout << dp[i][j] << ' ';
    }
    //    cout << endl;
    flag = 0;
  }
  return dp[s1.length()][s2.length()];
}

int main(){
  int n;
  cin >> n;
  while(n--) {
    cin >> s1 >> s2;
    cout << lcs() << endl;
  }
  
  return 0;
}

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

using namespace std;

#define debug(x) cout << #x << "==" << x << endl;

const int inf = 100000000;

typedef long long ll;

int solve() {

  string s, t;
  cin >> s >> t;

  // dp[i][j] := s_1,...s_i と t_1,...t_j に対するLCSの長さ
  // s[i] == t[j] なら dp[i-1][j-1] + 1
  // s[i] != t[j] なら max( dp[i-1][j], dp[i][j-1] )
  int dp[s.size()+1][t.size()+1];
  fill(dp[0], dp[s.size()+1], 0);
  for(int i = 0; i < s.size(); i++) {
    for(int j = 0; j < t.size(); j++) {
      if( s[i] == t[j] ) {
        dp[i+1][j+1] = dp[i][j] + 1;
      } else {
        dp[i+1][j+1] = max(dp[i][j+1], dp[i+1][j]);
      }
    }
  }

  return dp[s.size()][t.size()];


}


int main() {
  ios::sync_with_stdio(false);

  int N;
  cin >> N;

  for(int i = 0; i < N; i++) {
    cout << solve() << "\n";
  }


  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;
  
  for (int i = 0; i < m; i++) {
    for (int j = 0; j < n; j++) {
      if (X[i] == Y[j]) 
        if (i == 0 || j == 0) 
          c[i][j] = 1;
        else 
          c[i][j] = c[i - 1][j - 1] + 1;
      else
        if (i != 0 && j != 0) 
          c[i][j] = max(c[i][j - 1], c[i - 1][j]);
        else
          c[i][j] = 0;
      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;
}