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 <iostream>
#include <string>
#include <cstdio>

using namespace std;

int minSequenceSize(string x, string y)
{
    int x_len = x.size();
    int y_len = y.size();
    int map[x_len][y_len] = {};

    for (int i = 0; i < x_len; i++)
    {
        for (int j = 0; j < y_len; j++)
        {
            if (i == 0)
            {
                map[0][j] = 0;
                continue;
            }
            if (j == 0)
            {
                map[i][0] = 0;
                continue;
            }

            if (x[i] == y[j])
            {
                map[i][j] = map[i - 1][j - 1] + 1;
                continue;
            }

            if (x[i] != y[j])
            {
                map[i][j] = max(map[i - 1][j], map[i][j - 1]);
                continue;
            }
        }
    }
    return map[x_len - 1][y_len - 1];
}

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

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

        x = " " + x;
        y = " " + y;
        int ans = minSequenceSize(x, y);
        cout << ans << endl;
    }
}

C++: #include<iostream>
#include<algorithm>
#include<cstdio>
#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.size();
  int n = Y.size();
  int maxl = 0;
  X = ' '+X;
  Y = ' '+Y;
  for(int i = 1;i<=m;i++) c[i][0] = 0;
  for(int j = 1;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 {c[i][j] = max(c[i-1][j],c[i][j-1]);}
        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 ;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<(n); i++)
#define rep2(i,x,n) for(int i=x; i<(n); i++)
#define ALL(n) begin(n),end(n)
#define INF ((1<<30)-1)
#define LINF (1LL<<60)
#define EPS (1e-10)
typedef long long Int;
typedef pair<Int, Int> P;
typedef pair<int, int> pint;
struct cww{cww(){ios::sync_with_stdio(false);cin.tie(0);}}star;
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int q; cin>>q;
    for(int i=0; i<q; i++){
        string x,y;
        cin>>x>>y;
        int nx=(int)x.size();
        int ny= (int)y.size();
        vector<vector<Int>> dp(nx+1,vector<Int>(ny+1,0));
        for(int i=0; i<(int)x.size(); i++){
            for(int j=0; j<(int)y.size(); j++){
                if(x[i]==y[j]){
                    dp[i+1][j+1]=max(dp[i+1][j+1],dp[i][j]+1);
                }
                dp[i+1][j+1]=max({dp[i+1][j+1],dp[i][j+1],dp[i+1][j]});
            }
        }
        cout<<dp[nx][ny]<<endl;
    }
    return 0;
}

C++: #include <iostream>
#include <string>
#include <algorithm>
#include <math.h>
#include <string>
#include <utility>
using namespace std;

int n;
string a,b;


int main(){
	cin >> n;
	for (int i = 0; i < n; i++){
		cin >> a >> b;
		int t[1010][1010] = {};
		for (int i = 0; i < a.length(); i++){
			for (int j = 0; j < b.length(); j++){
				if (i == 0 || j == 0)t[i][j] = 0;
				else if (a[i] == b[i]){
					t[i + 1][j + 1] = t[i][j] + 1;
				}
				else t[i + 1][j + 1] = max(t[i + 1][j], t[i][j + 1]);
			}
		}
		cout << t[a.length()][b.length()] << endl;
	}
	return 0;
}

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

int main() {
  int q;
  cin >> q;
  for (int i=0;i<q;++i) {
    string str1,str2;
    cin >> str1 >> str2;
    int size1 = str1.size();
    int size2 = str2.size();
    int matrix[size1+1][size2+1];
    for (int j=0;j<=size1;++j)
      matrix[j][0] = 0;
    for (int j=0;j<=size2;++j)
      matrix[0][j] = 0;
    for (int j=0;j<=size1;++j) {
      for (int k=0;k<=size2;++k) {
	if (j<=0||k<=0) {
	  matrix[j][k] = 0;
	}
	else if (str1[j]==str2[k]) {
	  matrix[j][k] = 1 + matrix[j-1][k-1];
	}
	else {
	  matrix[j][k] = max(matrix[j][k-1],matrix[j-1][k]);
	}
      }
    }
    cout << matrix[size1][size2] << endl;
  }
}

int max(int a,int b) {
  if (a>b)
    return a;
  else
    return b;
}

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

int main()
{
    int q;
    cin >> q;
    for (int ii = 0; ii < q; ii++)
    {
        string X, Y;
        cin >> X >> Y;
        int x = X.size();
        int y = Y.size();
        int dp[x + 1][y + 1];
        memset(dp, 0, sizeof(dp));
        for (int i = 0; i < x; i++)
        {
            for (int j = 0; j < y; j++)
            {
                if (X[i] == Y[j])
                {
                    dp[i + 1][j + 1] = max({dp[i][j] + 1, dp[i + 1][j], dp[i][j + 1]});
                }
                else
                {
                    dp[i + 1][j + 1] = max(dp[i + 1][j], dp[i][j + 1]);
                }
            }
        }
        cout << dp[x][y] << endl;
    }
}

C++: // Longest Common Subsequence

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<string>
using namespace std;
#define MAX 1001

int make_lcs(string x, string y) {
	int lcs[MAX][MAX] = {};
	x = ' ' + x;
	y = ' ' + y;
	for (unsigned int i=0;i<x.length();i++) {
	for (unsigned int j=0;j<y.length();j++) {
	if (i!=0 && j!=0) {
	if (x[i] == y[j]) {
	lcs[i][j] = lcs[i-1][j-1] + 1;
	}
	else {
	lcs[i][j] = max(lcs[i-1][j], lcs[i][j-1]);
	}
	}
	}
	}
	return lcs[x.length()-1][y.length()-1];
}
int main() {
	int n;
	string x,y;
	cin >> n;
	for (int k=0;k<n;k++) {
	cin >> x >> y;
	cout << make_lcs(x,y) << endl;
	}
	return 0;
}