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<cstdio>
#include<string>
#include<algorithm>
#define Lens 1005

using namespace std;
string x, y;
int C[Lens][Lens];
int N;

int com(string x,string y)
{
	int m = x.length();
	int n = y.length();
	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]);
			}
		}
	return C[m][n];

}

int main()
{
	cin >> N;
	for (int i = 0; i < N; i++)
	{
		cin >> x >> y;
		int ans=com(x, y);
		cout << ans << endl;
	}


	return 0;
}

C++: #include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<vector>
#include<queue>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
using namespace std;

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int,int> PII;
typedef long long LL;

#define d(x)  cout<<#x<<" = "<<(x)<<endl;
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define REACH(i,c) for(typeof((c).rbegin()) i=(c).rbegin(); i!=(c).rend(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c,n) sort(c,c+n)
#define VSORT(c) sort((c).begin(),(c).end())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define DFOR(i,b,a) for(int i=(b)-1;i>=(a);--i)
#define DREP(i,n) DFOR(i,n,0)
#define INF 2000000000

const double EPS = 1e-10;
const double PI  = acos(-1.0);
////////////////////////////////////////////////
int q;
string X,Y;
int a[1010][1010];



int main()
{
	cin>>q;
	REP(i,q)
	{
		cin>>X>>Y;
		int m=SZ(X);
		int n=SZ(Y);
		X=' '+X;
		Y=' '+Y;
		FOR(i,1,m+1)
		{
			FOR(j,1,n+1)
			{
				if(X[i]==Y[j])a[i][j]=a[i-1][j-1]+1;
				else a[i][j]=max(a[i-1][j],a[i][j-1]);
			}
		}
		cout<<a[m][n]<<endl;
	}
	return 0;
}

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

int main() {
  std::ios::sync_with_stdio(false);
  cout.tie(0);
  cin.tie(0);
  int N;
  cin>>N;
  string S1,S2;
  for (int i=0; i<N; i++) {
    cin>>S1>>S2;
    int m=S1.length();
    int n=S2.length();
    S1=' '+S1;
    S2=' '+S2;
    int lcs[m+1][n+1];
    for (int i=1; i<=m; i++) {
      lcs[i][0]=0;
    }
    for (int j=1; j<=n; j++) {
      lcs[0][j]=0;
    }
    int maxl=0;
    for (int i=1; i<=m; i++) {
      for (int j=1; j<=n; j++) {
        if (S1[i]==S2[j]) {
          lcs[i][j]=lcs[i-1][j-1]+1;
        }
        else {
          lcs[i][j]=max(lcs[i-1][j],lcs[i][j-1]);
        }
        maxl=max(maxl,lcs[i][j]);
      }
    }
    cout<<maxl<<endl;
  }
  return 0;
}

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

template<typename A, size_t N, typename T>
void Fill(A (&array)[N], const T &val){
    std::fill( (T*)array, (T*)(array+N), val );
}

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

    int lcs[1010][1010];

    for (int i = 0; i < q; i++)
    {
        string x, y;
        cin >> x >> y;
        Fill(lcs, 0);
        for (int j = 1; j <= x.size(); j++)
        {
            for (int k = 1; k <= y.size(); k++)
            {
                if(x[j-1] == y[k-1]) lcs[j][k] = lcs[j-1][k-1] + 1;
                else lcs[j][k] = max(lcs[j-1][k], lcs[j][k-1]);
            }
        }
        cout << lcs[x.size()][y.size()] << endl;
    }

}

C++: #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(v) v.begin(), v.end()
typedef pair<int, int> P;
template <class T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
const vector<int> di = {-1, 0, 1, 0};
const vector<int> dj = {0, -1, 0, 1};
const int INF = 1001001001;

int q;
vector<pair<string, string>> dataset;

int main() {
  cin >> q;
  dataset.resize(q);

  rep(i, q) {
    string x, y;
    cin >> x >> y;
    dataset[i] = make_pair(x, y);
  }

  vector<int> ans;

  for (auto&& data : dataset) {
    string x, y;
    tie(x, y) = data;

    vector<vector<int>> dp(x.size() + 1, vector<int>(y.size() + 1, 0));

    rep(i, x.size()) {
      rep(j, y.size()) {
        if (x[i] == y[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]);
        }
      }
    }

    ans.push_back(dp[x.size()][y.size()]);
  }

  for (auto&& i : ans) {
    printf("%d\n", i);
  }
}

C++: #include<iostream>
#include<map>
#include<vector>
#include<algorithm>
#include<cmath>
#include<climits>
#include<ctime>
#include<cstring>
#include<stack>
#include<queue>
#include<sstream>
#include<string>
#include<set>
#include<array>
#include<cassert>

#define ALL(v) (v).begin(),(v).end()
#define REP(i,p,n) for(int i=p;i<(int)(n);++i)
#define rep(i,n) REP(i,0,n)
#define DUMP(list) cout << "{ "; for(auto nth : list){ cout << nth << " "; } cout << "}" << endl
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i);

using namespace std;

const int MAX=1001;
const int INF=1<<29;

int dp[MAX][MAX];

int main(){

	int n;
	cin >> n;

	rep(i,n){
		string a,b;
		cin >> a >> b;
	
		fill_n((int *)dp,sizeof(dp)/sizeof(int),0);
		
		rep(i,a.size()+1){
			rep(j,b.size()+1){
				if(i==0||j==0) dp[i][j]=0;
				else if(a[i-1]==b[j-1]) dp[i][j]=dp[i-1][j-1]+1;
				else dp[i][j]=max(dp[i][j-1],dp[i-1][j]);
			}
		
		}

		cout << dp[a.size()][b.size()] << endl;
	
	}

}