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 <cassert>
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <algorithm>
#include <bitset>
#include <complex>

#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#define rep(i,n) for(int i=0;i<(n); i++)

using namespace std;

static const int N=1001;
int lcs(string X,string Y){
	int c[N+1][N+1]; //二次元配列の作成
	int m=X.size();
	int n=Y.size();
	int maxl=0;
	X = ' '+X;
	Y = ' '+Y; //それぞれ文字列の先頭に空白を挿入
	rep(i,m) c[i][0]=0;
	rep(j,n) 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(){
	cin.tie(0);
    ios::sync_with_stdio(0); //この2行はより速度を向上させる
	// 追加２, 以降 cin の入力元が 'input.txt' になる
	//提出時に消す！！
	//td::ifstream in("sample.txt");
	//std::cin.rdbuf(in.rdbuf());

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

C++: // AOJ ALDS1_10_C Longest Common Subsequence

#include <algorithm>
#include <iostream>

using namespace std;

// returns the length of the longest common subsequence
// of x[i:n] and y[j:m]
int llcs(string x, string y) {
  int n = x.length();
  int m = y.length();
  int dp[n + 1][m + 1];
  for (auto arr : dp) {
    fill(arr, arr + m + 1, 0);
  }
  for (int i = n - 1; i >= 0; --i) {
    for (int j = m - 1; j >= 0; --j) {
      int res = -1;
      res = max(dp[i + 1][j], dp[i][j + 1]);
      if (x[i] == y[j])
        res = max(res, dp[i + 1][j + 1] + 1);
      dp[i][j] = res;
    }
  }
  return dp[0][0];
}

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

  string x, y;
  // print length of longest common subsequence of x and y
  while (cin >> x >> y) {
    cout << llcs(x, y) << endl;
  }
}

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

using namespace std;

int main(){
  string X,Y;
  int n;
  cin>>n;
  int ans[n];
  int l=0;

  for(int i=0;i<n;i++){
    ans[i]=0;
  }

  for(int m=0;m<n;m++){
  cin>>X>>Y;
 int N[X.size()+1][Y.size()+1];

  for(int i=0;i<=X.size();i++){
    for(int j=0;j<=Y.size();j++){

      N[i][j]=0;
}
  }

  /*
  for(int i=0;i<X.size();i++){
    cout<<X[i]<<endl;
  }

for(int i=0;i<Y.size();i++){
    cout<<Y[i];
  }
  */

  /* 
for(int i=0;i<=X.size();i++){
  N[i][0]=0;
  }

for(int i=0;i<=Y.size();i++){
  N[0][i]=0;
  }
  */

 int point;

  for(int i=1;i<=X.size();i++){
    for(int j=1;j<=Y.size();j++){
      if(X[i-1]==Y[j-1]){
	point=1;
	
      }else{
	point=0;
      }
       N[i][j]=max({N[i-1][j],N[i][j-1],N[i-1][j-1]+point});
       point=0;
}
   
  }
  ans[l]=N[X.size()][Y.size()];
  l++;
  // cout<<N[X.size()][Y.size()]<<endl;
  /*
  //answer
  for(int i=0;i<=X.size();i++){
    for(int j=0;j<=Y.size();j++){

      cout<<N[i][j]<<" ";
      if(j==Y.size()){
	cout<<endl;
      }
}
  }
  */

  }
  cout<<ans[0]<<endl;
 cout<<ans[1]<<endl;
 cout<<ans[2]<<endl;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int, int>;

int dp[1001][1001];
int main() {
  int q;
  cin >> q;
  rep(qq, q) {
    string x, y;
    cin >> x >> y;
    int len_x = x.size();
    int len_y = y.size();
    rep(i, len_x) rep(j, len_y) {
      if (x[i] == y[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]);
    }
    cout << dp[len_x][len_y] << endl;
  }
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define NIL -1
#define MAX 1000

static const int N = 1000;

int lcs(string X, string Y)
{
    int dp[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){
        dp[i][0] = 0;
    }
    for (int j = 0; j <= n; ++j){
        dp[0][j] = 0;
    }

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


int main()
{
    int n;
    cin >> n;
    string X, Y;
    vector<int> v;

    rep(i, n)
    {
        cin >> X >> Y;
        v.push_back(lcs(X,Y));
    }

    rep(i, v.size()) cout << v[i] << 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], maxl = 0, i, j;
  int m = x.size();
  int n = y.size();

  x = ' ' + x;
  y = ' ' + y;
 
  for(i = 1; i <= m; i++) c[i][0] = 0;
  for(i = 1; i <= n; i++) c[0][i] = 0;

  for(i = 1; i <= m; i++){#include <iostream>

    for(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 x, y;
  int q, i;

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