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>

#define MOD 1000000007
#define INF (1<<30)
#define INFL (1<<62)
#define pe(str) return cout<<(str)<<endl,0
#define px(str) cout<<(str)<<endl,exit(0)
#define accu(ac,v) cout<<setprecision(ac)<<v<<endl
#define bpc(a) __builtin_popcount(a)
#define pr(str) cout<<(str)<<endl
#define prpr(str) cout<<str<<endl
#define db(str) cerr<<"debug:"<<(str)<<endl
#define dbdb(str) cerr<<"debugs:"<<str<<endl
#define re(i,n) for(int i=0;i<(n);i++)
#define rre(i,n) for(int i=(n);i>=0;i--)
#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define rrep(i,a,b) for(int i=(b);i>=(a);i--)
#define bw(a,b,c) (((a)<=(b))&&((b)<=(c)))
#define hello cout<<"hello"<<endl
#define spre(a) setprecision(a)
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
#define s3(C,T,F) ((C)?(T):(F))
#define max3(a,b,c) max((a),max((b),(c)))
#define min3(a,b,c) min((a),min((b),(c)))
#define max4(a,b,c,d) max((a),max((b),max((c),(d))))
#define min4(a,b,c,d) min((a),min((b),min((c),(d))))
#define enl cout<<endl
#define declare(t,n) t n;cin>>n

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int,int> pii;
typedef complex<int> point;

template<class InputIterator>
void dump(InputIterator first,InputIterator last,char delim=' '){
	for(InputIterator it=first;it!=last;it++){
		if(it!=first)cout<<delim;
		cout<<*it;
	}
}

ull p(ull x,ull y){
	if(y==0) return 1;
	ull A=p(x,y/2)%MOD;
	return (y&1?((A*A)%MOD*x)%MOD: (A*A)%MOD);
	// return (y&1?((A*A)*x):(A*A));
}

template<class T>
void swp(T &a,T &b){
	T t=a; a=b; b=t;
}

int main(void){
	int dp[1001][1001];
	string a,b;
	int n;
	cin>>n;

	while (n--) {
		cin>>a>>b;
		re(i,a.size()) re(j,b.size()) dp[i][j]=0;
		rep(i,1,a.size()+1) rep(j,1,b.size()+1) dp[i][j]=max3(dp[i-1][j-1]+(a[i-1]==b[j-1]),dp[i-1][j],dp[i][j-1]);
		cout<<dp[a.size()][b.size()]<<endl;
	}
	return 0;
}

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

int main()
{
	int q, t1, t2;
	string s1, s2;
	const int maxS = 10;
	int m[maxS][maxS];

	cin >> q;

	for (int i = 0; i < q; i++) {

		for (int i = 0; i < maxS; i++)
			for (int j = 0; j < maxS; j++)
				m[i][j] = 0;

		cin >> s1 >> s2;

		t1 = s1.size() - 1;
		t2 = s2.size() - 1;

		if (s1[0] == s2[0])
			m[0][0] = 1;

		for (int i = 0; i < t1; i++) {
			int f = 0;
			if (s1[i + 1] == s2[0])
				f = 1;
			m[i + 1][0] = max(m[i][0], f);
		}

		for (int j = 0; j < t2; j++) {
			int f = 0;
			if (s2[j + 1] == s1[0])
				f = 1;
			m[0][j + 1] = max(m[0][j], f);
		}

		for (int i = 0; i < t1; i++) {
			for (int j = 0; j < t2; j++) {
				if (s1[i + 1] == s2[j + 1])
					m[i + 1][j + 1] = m[i][j] + 1;
				else
					m[i + 1][j + 1] = max(m[i][j + 1], m[i + 1][j]);
			}
		}

		cout << m[t1][t2] << endl;
	}
	return 0;
}

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;
 
 int c[4001][4001]{};
signed main(){
    int n;
    scanf("%d",&n);
    char a[5000];
char b[5000];
    for(int m=0;m<n;m++){
	scanf("%s%s",a,b);
int d,e;
d=strlen(a);
e=strlen(b);
for(int t=0;t<=d;t++){
    for(int w=0;w<=d;w++)c[t][w]=0;
    }
for(int x=0;x<d;x++){
    for(int y=0;y<e;y++){
	if(a[x]==b[y])c[x+1][y+1]=c[x][y]+1;
	else c[x+1][y+1]=max(c[x][y+1],c[x+1][y]);
	}
    }
    printf("%d\n",c[d][e]);
	}
}

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

int main(){
	int q;
	std::string a, b;
	std::vector< int > dp(1001*1001,0);
	
	std::cin >> q;
	
	for(int i=0;i<q;++i){
		std::cin >> a >> b;
		
		for(int x=1;x<=a.length();++x){
			for(int y=1;y<=b.length();++y){
				if(a[x] == b[y]){
					dp[y * 1001 + x] = dp[(y - 1) * 1001 + (x - 1)] + 1;
				}else{
					dp[y * 1001 + x] = std::max(dp[(y - 1) * 1001 + x], dp[y * 1001 + (x - 1)]);
				}
			}
		}
		std::cout << dp[b.length() * 1001 + a.length()] << std::endl;
	}
	
	return 0;
}

C++: #include<iostream>
#include<vector>
#include<string>
#include<algorithm>
using namespace std;
string s1,s2;
int memo[1001][1001];

int solve(int l1,int l2){
  if(l1 < 0 or l2 < 0)return 0;
  if(memo[l1][l2] >= 0)return memo[l1][l2];
  //cout << s1[l1] << s2[l2] << endl;
  if(s1[l1] == s2[l2]){
    return memo[l1][l2] = solve(l1 - 1,l2 - 1) + 1;
  }
  return memo[l1][l2] = max(solve(l1,l2-1), solve(l1-1,l2));
}
int main(){
  int n;
  cin >> n;
  for(int i = 0;i < n;i++){
    fill(memo[0],memo[100],-1);
    cin >> s1 ;
    cin >> s2;
    cout << solve(s1.length(),s2.length()) - 1 << endl;
  }
}

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

using namespace std;

typedef long long ll;

const int INF = 1e9;

int cal(string x, string y)
{
  int n1 = x.size(), n2 = y.size();
  vector<vector<int> > dp(n1 + 5, vector<int>(n2 + 5, 0));
  for (int i = 0; i < n1; ++i) {
    for (int j = 0; j < n2; ++j) {
      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]);
      }
    }
  }
  return dp[n1][n2];
}

int main()
{
  int n = 0;
  fscanf(stdin, "%d", &n);
  for (int i = 0; i < n; ++i) {
    string x, y;
    cin >> x >> y;
    int len = cal(x, y);
    fprintf(stdout, "%d\n", len);
  }
  return 0;
}

C++: #include<iostream>
#include<string>
#include<cstring>
using namespace std;
int dp[1000][1000];
string s1,s2;
int len1,len2;

int Str(){
	memset(dp,0,sizeof(dp));
	for(int i=1;i<=len1;i++)
		for(int j=1;j<=len2;j++){
			if(s1[i]==s2[j]){
				dp[i][j] = dp[i-1][j-1]+1;
			}else{
				dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
			}
		}
		return dp[len1][len2];
	}
	
	int main(){
		int n;
		cin>>n;
		while(n--){
			cin>>s1>>s2;
			len1=s1.size();
			len2=s2.size();
			s1=' '+s1;
			s2=' '+s2;
			cout<<Str()<<endl;
		}
		return 0;
	}