Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)
	for i := 0; i < n; i++ {
		x := getNextString(scanner)
		y := getNextString(scanner)

		fmt.Fprintln(writer, lcs(x, y))
	}

	writer.Flush()
}

func lcs(x, y string) int {
	lx := len(x)
	ly := len(y)
	dp := make([][]int, lx+1)
	for i := 0; i <= lx; i++ {
		dp[i] = make([]int, ly+1)
	}
	for i := 0; i < lx; i++ {
		for ii := 0; ii < ly; ii++ {
			if x[i] == y[ii] {
				dp[i+1][ii+1] = dp[i][ii] + 1
				continue
			}
			dp[i+1][ii+1] = dp[i][ii+1]
			if dp[i+1][ii] > dp[i+1][ii+1] {
				dp[i+1][ii+1] = dp[i+1][ii]
			}
		}
	}
	return dp[lx][ly]
}

C++: 
#include<iostream>

int main(){
  int n;
  std::string x,y;
  std::cin>>n;
  int a[1000][1000];
  int b[n];

  for(int i=0;i<n;i++){
    std::cin>>x;
    std::cin>>y;
    for(int j=0;j<1000;j++){
      for(int k=0;k<1000;k++){
	a[j][k]=0;
      }
    }
    for(int j=0;j<=x.size();j++){
      for(int k=0;k<=y.size();k++){
	if(x[j]==y[k]){
	  a[j+1][k+0]=a[j][k]+1;
	}else{
	  if(a[j][k+1]>a[j+1][k]){
	    a[j+1][k+1]=a[j][k+1];
	  }else{
	    a[j+1][k+1]=a[j+1][k];
	  }
	}
      }
    }
    b[i]=a[x.size()][y.size()];
  }

  for(int i=0;i<n;i++){
  std::cout<<b[i]<<"\n";
  }

  return 0;
}

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

using namespace std;

int main(){
  int n;
  int k;
  int count;
  int max;
  cin>>n;
  char X[1001];
  char Y[1001];
  for(int i=0;i<n;i++){
    cin>>X;
    cin>>Y;
    k=0;
    max=0;
    for(int a=0;X[a]!='\0';a++){
    count=0;
      for(int i=a;X[i]!='\0';i++){
	for(int j=k;Y[j]!='\0';j++){
	  if(X[i]==Y[j]){
	    count++;
	    k=j;
	    break;
	  }
	}
      }
      if(max<count)max=count;
    }
    cout<<max<<endl;
    
  }
  return 0;
}

C++: #include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<map>
#include<set>
#include<cstdio>
#include<cmath>
#include<deque>
#include<numeric>
#include<queue>
#include<stack>
#include<cstring>
#include<limits>
#include<functional>
#include<unordered_set>
#include<iomanip>
#include<cassert>
#include<regex>
#include<bitset>
#include<complex>
#include<chrono>
#include<random>
#define rep(i,a) for(int i=(int)0;i<(int)a;++i)
#define rrep(i,a) for(int i=(int)a-1;i>=0;--i)
#define REP(i,a,b) for(int i=(int)a;i<(int)b;++i)
#define RREP(i,a,b) for(int i=(int)a-1;i>=b;--i)
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(),x.end()
using ll=long long;
constexpr ll mod = 1e9 + 7;
constexpr ll INF = 1LL << 60;

ll gcd(ll n, ll m) {
	ll tmp;
	while (m!=0) {
		tmp = n % m;
		n = m;
		m = tmp;
	}
	return n;
}

ll lcm(ll n, ll m) {
	return abs(n) / gcd(n, m)*abs(m);//gl=xy
}
 
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;
}
 
using namespace std;

int LCS(string s,string t){
  int n=s.size(),m=t.size();
  vector<vector<int>>dp(n+1,vector<int>(m+1));
  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]);
    }
  }
  return dp[n][m];
}


void solve(){
  int t;
  cin>>t;
  while(t--){
    string s,t;
    cin>>s>>t;
    cout<<LCS(s,t)<<"\n";
  }
}

int main(){
	ios::sync_with_stdio(false);
  cin.tie(0);
	cout<<fixed<<setprecision(15);
  solve();
	return 0;
}

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

using namespace std;

int dp[1501][1501];

int LCS(string x, string y){
  memset(dp, 0, sizeof(dp));
  if(x[0] == y[0])dp[0][0] = 1;
  for(int i=1;i<x.length();i++){
    dp[i][0] = dp[i-1][0];
    if(x[i] == y[0])dp[i][0] = 1;
  }
  for(int i=1;i<y.length();i++){
    dp[0][i] = dp[0][i-1];
    if(y[i] == x[0])dp[0][i] = 1;
  }
  for(int i=1;i<x.length();i++){
    for(int j=1;j<y.length();j++){
      if(x[i] == y[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[x.length()-1][y.length()-1];
}

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

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

static const N = 100;

int main(){
	int n, p[N+1], m[N+1][N+1];
	cin >> n;
	for (int i=1; i<=n; i++){
		cin >> p[i-1] >> p[i];
	}

	for (int i=1; i<=n; i++) m[i][i] = 0;
	for (int l=2; l <= n; l++){
		for (int i=1; i<=n-l+1; i++){
			int j = i + l - 1;
			m[i][j] = 1 << 21;
			for (int k = i; k<= j - 1; k++){
				m[i][j] = min(m[i][j], m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]);
			}
		}
	}

	cout << m[1][n] << endl;

	return 0;
}

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

int max(int a, int b, int c);

int main(){
    int n;
    std::cin >> n;
    std::string str1;
    std::string str2;
    for(int i=0;i<n;i++){
        std::cin >> str1;
        std::cin >> str2;
        int size1 = str1.size();
        int size2 = str2.size();
        int dp[size1+1][size2+1];
        dp[0][0] = 0;
        for(int j=0;j<=size1;j++){
            dp[j][0] = 0;
        }
        for(int j=0;j<=size2;j++){
            dp[0][j] = 0;
        }

        for(int j=1;j<=size1;j++){
            for(int k=1;k<=size2;k++){
                if(str1[j-1]==str2[k-1]){
                    dp[j][k] = max(dp[j-1][k],dp[j-1][k-1] + 1,dp[j][k-1]);
                }else{
                    dp[j][k] = max(dp[j-1][k],dp[j-1][k-1],dp[j][k-1]);
                }
            }
        }

        std::cout << dp[size1][size2] << std::endl;
    }
    return 0;
}

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

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;
  for(int i=0;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;
}