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<algorithm>
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;
  C[0][0] = 0;
  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]);
    }
  }javascript:void(0)

  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;
typedef long long ll;
#define _USE_MATH_DEFINES
#include <math.h>
#define rep(i,n) for(int i = 0;i < n;i++)
#define NIL = -1;

ll gcd(long long a,long long b) {
    if (a < b) swap(a,b);
    if (b == 0) return a;
    
    return gcd(b,a%b);
}

ll lcm(ll a,ll b){
    a / gcd(a,b) * b;
}
const ll mod = 1e9 + 7;

int dx[4] = {0,1,0,-1};
int dy[4] = {1,0,-1,0};

const ll INF = 1e9;
/////////////////////////////////////////////////////////////////////////////////////////
int n,m;
string s,t;
int dp[2000][2000];
void solve(){
    for (int i = 0;i < n;i++){
        for (int j = 0;j < m;j++){
            if (s[i] == t[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]);
            }
        }
    }
     cout << dp[n][m] << endl;
}
int main(){
    int q;
    cin >> q;
    vector<string> x(q),y(q);
    vector<int> ans(q);
    

    for (int i = 0;i < q;i++){
        cin >> s >> t;
        n = s.size();
        m = t.size();
        solve();
    }

    return 0;
}

C++: #include<iostream>
#include<string>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
#include<vector>
#include<functional>
#include<iomanip>
#include<queue>
#include<cassert>
#include<tuple>
#include<set>
#include<map>
#include<list>
#include<bitset>

#define PB push_back
#define ALL(a)  (a).begin(),(a).end()
#define DWN(a)  (a).begin(),(a).end(), greater<int>()
#define rep(i, m) for (int i = 0; i < m; i++)
#define REP(i, n, m) for (int i = n; i < m; i++)

#define mod 1000000007

using namespace std;

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

const int dx[4] = { 1, 0, -1, 0 };
const int dy[4] = { 0, 1, 0, -1 };
const int INF = (int)1e9;

int q;
string s, t;
int dp[151][151];

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	cin >> q;
	rep(k, q) {
		cin >> s >> t;
		rep(i, q) rep(j, q) dp[i][j] = 0;
		rep(i, s.size()) {
			rep(j, t.size()) {
				if (s[i] == t[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[s.size()][t.size()] << "\n";
	}
	return 0;
}

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

template<class T> inline void chmax(T &a, const T &b) { if(a < b) a = b; }

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

	int q;
	cin >> q;

	while(q--) {
		string a, b;
		cin >> a >> b;

		const int n = a.size();
		const int m = b.size();

		vector<vector<int>> dp(n + 2, vector<int>(m + 2, 0));
		for(int i = 0; i <= n; ++i) {
			for(int j = 0; j <= m; ++j) {
				if(a[i] == b[j]) {
					chmax(dp[i + 1][j + 1], dp[i][j] + 1);
				}
				else {
					chmax(dp[i + 1][j + 1], dp[i][j]);
					chmax(dp[i + 1][j], dp[i][j]);
					chmax(dp[i][j + 1], dp[i][j]);
				}
			}
		}

		cout << dp[n][m] << endl;
	}

	return EXIT_SUCCESS;
}

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

constexpr int MAX_XY = 1010;

int lx, ly, q, dp[MAX_XY][MAX_XY];
std::string sx, sy;

void fill_dp(){
    for(int i = 1; i <= lx; ++i){
        for(int j = 1; j <= ly; ++j){
            if(sx[i - 1] == sy[j - 1]) dp[i][j] = dp[i - 1][j - 1] + 1;
            else dp[i][j] = std::max(dp[i - 1][j], dp[i][j - 1]);
        }
    }
}

void solve(){
    fill_dp();
    std::cout << dp[lx][ly] << std::endl;
    return;
}

int main(){
    std::cin >> q;
    
    for(int i = 0; i < q; ++i){
        std::cin >> sx >> sy;
        lx = sx.size(), ly = sy.size();
        solve();
    }
    return 0;
}