Go: package main

import "fmt"

func initialize_grid(width int,height int)[][]int{
	var grid [][]int
	for i:=0;i<height+1;i++{
		var grid_row  []int
		for j:=0;j<width+1;j++{
			grid_row = append(grid_row,0)
		}
		grid = append(grid,grid_row[:])
	}
	return grid
}

func ma(x int,y int)int{
	if x >= y{
		return x
	}else{
		return y
	}
}

func main()  {
	//Take input
	var num int
	var st1,st2 string
	var string_pairs [][]string
	fmt.Scan(&num)
	for i:=0;i<num;i++{
		var string_pair []string
		fmt.Scan(&st1)
		fmt.Scan(&st2)
		string_pair = append(string_pair,st1,st2)
		string_pairs = append(string_pairs,string_pair)
	}
	//DP
	//initialize grid
	for i:=0;i<num;i++{
		string_1 := string_pairs[i][0]
		string_2 := string_pairs[i][1]

		dp := initialize_grid(len(string_2),len(string_1))

		for j:=1;j<len(string_1)+1;j++{
			for k:=1;k<len(string_2)+1;k++{
				if string_1[j-1] == string_2[k-1]{
					dp[j][k] = dp[j-1][k-1] + 1
				}else{
					dp[j][k] = ma(dp[j-1][k],dp[j][k-1])
				}
			}
		}
		fmt.Println(dp[len(string_1)][len(string_2)])
	}
}

C++: #include<bits/stdc++.h>
using namespace std;
int a[1003][1003];
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        string x,y;
        cin>>x>>y;
        int len1=x.size();
        int len2=y.size();

        memset(a,0,sizeof(a));
        for(int i=0; i<len1; i++)
        {
            for(int j=0; j<len2; j++)
            {
                if(x[i]==y[j])
                {
                    a[i+1][j+1]=a[i][j]+1;
                }
                else a[i+1][j+1]=max(a[i][j+1],a[i+1][j]);
            }
        }
        cout<<a[len1][len2]<<endl;
    }

}

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

using namespace std;

int LCSLength(string X, string Y){
    int m = X.size();
    int n = Y.size();
    int c[m+1][n+1];
    int maxLength = 0;
    for(int i = 1; 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 if(c[i-1][j] >= c[i][j-1]) c[i][j] = c[i-1][j];
            else c[i][j] = c[i][j-1];
            maxLength = max(maxLength, c[i][j]);
        }
    }
    return maxLength;
}

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

C++: #include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

int lcs(string x, string y) {
    int lx = x.size(), ly = y.size();
    vector<vector<int>> dp(lx+1, vector<int>(ly+1, 0));
    for (int i=1;i<=lx; i++){
        for (int j=1; j<=ly; j++){
            if (x[i-1] == y[j-1]) {
                dp[i][j] = dp[i-1][j-1]+1;
            } else {
                dp[i][j]= max(dp[i-1][j], dp[i][j-1]);
            }
        }
    }
    return dp[lx][ly];
}

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

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

    return 0;
}

C++: #include<string>
int lcs(std::string s, std::string t) {
    const int M = s.size(), N = t.size();
    int dp[M+1][N+1] = {};
    for(int i=0; i<M; ++i)
        for(int j=0; j<N; ++j)
            if(s[i] == t[j]) dp[i+1][j+1] = dp[i][j] + 1;
            else dp[i+1][j+1] = std::max(dp[i+1][j], dp[i][j+1]);
    return dp[M][N];
}
#include<iostream>
using namespace std;
int main(){
    int n;
    cin>>n;
    for(int i=0;i<n;++i){
        string s,t;
        cin>>s>>t;
        cout<<lcs(s,t)<<endl;
    }
}

C++: #include <stdio.h>
#include <iostream>
#include <utility>
#include <algorithm>
#include <math.h>
#include <vector>
using namespace std;
int dp[1001][1001] = {};

int getLCS(string X, string Y)
{
    for (int i = 1; i <= X.size(); i++)
    {
        for (int j = 1; j <= Y.size(); j++)
        {
            dp[i][j] = X[i - 1] == Y[j - 1] ? dp[i - 1][j - 1] + 1 : max(dp[i - 1][j], dp[i][j - 1]);
        }
    }
    return dp[X.size()][Y.size()];
}

int main()
{
    int q;
    string X, Y;
    cin >> q;
    for (int i = 0; i < q; i++)
    {
        cin >> X >> Y;
        cout << getLCS(X, Y) << "\n";
    }
    return 0;
}

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

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

typedef long long ll;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> P;
typedef tuple<int,int,int> tpl;

#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define SORT(c) sort((c).begin(),(c).end())
#define REVERSE(c) reverse((c).begin(),(c).end())
#define LB(a,x) lower_bound((a).begin(), (a).end(), x) - (a).begin()
#define UB(a,x) upper_bound((a).begin(), (a).end(), x) - (a).begin()

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define RFOR(i,a,b) for(int i=(a)-1;i>=(b);--i)
#define RREP(i,n) RFOR(i,n,0)

#define en "\n"

const double EPS = 1e-9;
const double PI  = acos(-1.0);
const int INT_INF = 2147483647;
const long long LL_INF = 1LL<<60;
const long long MOD = 1000000007;

#define CLR(a) memset((a), 0, sizeof(a))

#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }

int main(void){
    int q; cin >> q;
    REP(i,q){
        string S,T; cin >> S >> T;
        int dp[S.size()+1][T.size()+1]; CLR(dp);
        REP(i,S.size())REP(j,T.size()){
            if(S[i] == T[j]) chmax(dp[i+1][j+1], dp[i][j]+1);
            chmax(dp[i+1][j+1], dp[i][j+1]);
            chmax(dp[i+1][j+1], dp[i+1][j]);
        }
        cout << dp[S.size()][T.size()] << en;
    }
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
int dp[2][1010];
int main(){
  int q;
  cin>>q;
  for(int cn=0;cn<q;cn++){
    string x,y;
    cin>>x>>y;
    memset(dp,0,sizeof(dp));
    for(int i=0;i<x.size();i++){
      int nw=i%2;
      int nt=!nw;
      for(int k=0;k<1010;k++)dp[nt][k]=0;
      for(int j=0;j<y.size();j++){
	if(j)dp[nw][j]=max(dp[nw][j],dp[nw][j-1]);
	if(x[i]==y[j])dp[nt][j+1]=max(dp[nt][j+1],dp[nw][j]+1);
	dp[nt][j]=max(dp[nt][j],dp[nw][j]);
      }
    }
    int ans=0;
    for(int i=0;i<1010;i++)ans=max(ans,dp[x.size()%2][i]);
    cout<<ans<<endl;
  }
  return 0;
}

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

class TLcsSolver
{
    int FTable[1000][1000];
    const char* FArray1;
    const char* FArray2;
    const int Fn1;
    const int Fn2;

    int Count(int i, int j)
    {
        if(i == 0 || j == 0) return 0;
        if(FArray1[i-1] == FArray2[j-1]){
            return FTable[i-1][j-1] + 1;
        }
        return std::max(FTable[i-1][j], FTable[i][j-1]);
    }
    void Solve()
    {
        for(std::size_t i = 1; i < Fn1; ++i){
            for(std::size_t j = 1; j < Fn2; ++j){
                FTable[i][j] = Count(i, j);
            }
        }
    }
public:
    TLcsSolver(const char* a, const char* b)
     : FArray1(a), FArray2(b)
     , Fn1(std::strlen(a)), Fn2(std::strlen(b))
    {
        Solve();
    }
    int Answer()const
    {
        return FTable[FArray1.size()][FArray2.size()];
    }
};

int main()
{
    int n;
    std::scanf("%d", &n);
    char a[1000];
    char b[1000];
    for(int i = 0; i < n; ++i){
        std::fgets(a, 1000, stdin);
        std::fgets(b, 1000, stdin);
        std::printf("%d", TLcsSolver(a, b).Answer());
    }
    return 0;
}