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>
using namespace std;

int lcs(string X, string Y) {
  int cs[1000][1000];
  int m = X.size();
  int n = Y.size();
  int answer = 0;
  for (int i = 0; i < m; i++) cs[m][0] = 0;
  for (int i = 0; i < n; i++) cs[0][n] = 0;

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

  return answer;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  int n;
  cin >> n;

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

  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

#define _GLIBCXX_DEBUG
#define all(v) (v).begin(),(v).end()

using ll=long long;
using pii=pair<int, int>;
using vi=vector<int>;
using vii=vector<vector<int>>;

const ll LINF=1LL<<60;
const int INF=1<<29;
const int MOD=1e9+7;

template<typename T>
T chmin(T &a, T b){
    if(a > b){ a=b; return true;}
    return false;
}

template<typename T>
T chmax(T &a, T b){
    if(a < b){ a=b; return true;}
    return false;
}

int main(){
    int q; cin >> q;
    while(q--){
        string X, Y;
        cin >> X >> Y;

        vii dp(X.size()+1, vi(Y.size()+1, 0));
        for(int i=0; i<X.size(); i++){
            for(int j=0; j<Y.size(); j++){
                if(X[i] == Y[j]) chmax(dp[i+1][j+1], dp[i][j]+1);
                chmax(dp[i+1][j+1], max(dp[i+1][j], dp[i][j+1]));
            }
        }

        cout << dp[X.size()][Y.size()] << endl;
    }
    return 0;
}

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

template<class T>
T myMin(const T& arg){
	return arg;
}
template<class F, class... S>
F myMin(const F& first, const S&... second){
	F m = myMin(second...);
	if (m > first){
		return first;
	}else{
		return m;
	}
}
int f(std::string::iterator str1, const std::string& str2, const std::vector<int>& vec){
	std::vector<int> new_v;
	new_v.push_back(vec[0] + 1);
	{
		auto v = vec.begin() + 1;
		for (auto i = str2.begin(); i != str2.end(); ++i, ++v){
			if (*i == *str1){
				new_v.push_back(myMin(*v, *(v - 1), new_v.back()));
			}else{
				new_v.push_back(myMin(*v + 1, new_v.back() + 1));
			}
		}
	}
	if (*(++str1) != '\0'){
		return f(str1, str2, new_v);
	}else{
		return new_v.back();
	}
}
int main(){
	int n;
	std::cin >> n;
	for (int i = 0; i < n; ++i){
		std::string str1, str2;
		std::cin >> str1 >> str2;
		std::vector<int> vec;
    vec.push_back(0);
		for (int j = 0; j < str2.size(); ++j){
			vec.push_back(j);
		}
		std::cout << (str1.size() + str2.size() - f(str1.begin(), str2, vec)) / 2 << "\n";
	}
}

C++: /* Dynamic Programming C/C++ implementation of LCS problem */
#include <cstdio>
#include <iostream>
#include <string>
using namespace std;

int max(int a, int b);
/* Returns length of LCS for X[0..m-1], Y[0..n-1] */
int lcs( string X, string Y, int m, int n ) {
    int L[m + 1][n + 1];
    int i, j;
    /* Following steps build L[m+1][n+1] in bottom up fashion. Note
       that L[i][j] contains length of LCS of X[0..i-1] and Y[0..j-1]*/

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

 //int index = L[m][n];

 /**if (index == 0) {printf("*"); return 0;}
 char lcs[index+1];
 lcs[index] = '\0'; // Set the terminating character

    // Start from the right-most-bottom-most corner and
    // one by one store characters in lcs[]
    i = m,
    j = n;
    while (i > 0 && j > 0 )
    {
        // If current character in X[] and Y are same, then
        // current character is part of LCS
        if (X[i-1] == Y[j-1])
        {
            lcs[index-1] = X[i-1]; // Put current character in result
            i--; j--; index--;     // reduce values of i, j and index
        }

            // If not same, then find the larger of two and
            // go in the direction of larger value
        else if (L[i-1][j] > L[i][j-1])
            i--;
        else
            j--;
    }

    printf("%s\n",lcs);**/

    /* L[m][n] contains length of LCS for X[0..n-1] and Y[0..m-1] */
    return L[m][n];
}

/* Utility function to get max of 2 integers */
int max(int a, int b) {
    return (a > b)? a : b; }

/* Driver program to test above function */
int main() {
    int N;
    scanf("%d",&N);
    for (int i = 0; i < N; i++) {
        int m ;
        int n ;
        string X;
        string Y;
        cin >> X >> Y;
        m = X.length();
        n = Y.length();
        cout << lcs(X, Y, m, n) << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;
int A[1005][1005]={};

int main() {
  int i,j,k,q;
  cin >> q;
  string a,b;
  for(i=0;i<q;i++) {
    cin  >> a >> b;
    int al = a.size();
    int bl = b.size();
    for(j=1;j<=al;j++) {
      for(k=1;k<=bl;k++) {
        if(a[j]==b[k]) {
          A[j][k]=A[j-1][k-1]+1;
        } else {
          A[j][k]=max(A[j][k-1],A[j-1][k]);
        }
      }
    }
    cout << A[al][bl] << endl;
  }
  return 0;
}

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

using namespace std;

int main () {

    int N, m, n, i, j, k, c[1001][1001];
    string x, y;

    cin >> N;

    for (k = 0; k < n; k++) {
        cin >> x >> y;
        m = x.size ();
        n = y.size ();

        for (i = 1; i < m + 1; i++) {
            for (j = 1; j <= n + 1; j++) {

                if (x[i - 1] == y[j - 1]) {
                    c[i][j] = c[i - 1][j - 1] + 1;
                } else {
                    c[i][j] = max (c[i - 1][j], c[i][j - 1]);
                }

            }
        }

    cout << c[p][q] << endl;

    }

}