Go: package main

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

// define
var (
	sc = bufio.NewScanner(os.Stdin)
)

func bordersInt(in_map [][]int, invalid int) [][]int{
	H, W := len(in_map), len(in_map[0])
	out_map := make([][]int, H+2)
	for h:=0; h<H+2; h++ {
		out_map[h] = make([]int, W+2)
		for w:=0; w<W+2; w++ {
			out_map[h][w] = invalid
		}
	}
	for h:=0; h<H; h++{
		for w:=0; w<W; w++{
			out_map[h+1][w+1] = in_map[h][w] 
		}
	}
	return out_map
}

func bordersString(in_map [][]string, invalid string) [][]string{
	H, W := len(in_map), len(in_map[0])
	out_map := make([][]string, H+2)
	for h:=0; h<H+2; h++ {
		out_map[h] = make([]string, W+2)
		for w:=0; w<W+2; w++ {
			out_map[h][w] = invalid
		}
	}
	for h:=0; h<H; h++{
		for w:=0; w<W; w++{
			out_map[h+1][w+1] = in_map[h][w] 
		}
	}
	return out_map
}

func scanIntLine(len int) []int{
	arr := make([]int, len)
	for i:=0; i<len; i++{
		sc.Scan()
		tmp, err := strconv.Atoi(sc.Text())
		if err == nil{
			arr[i] = tmp
		}
	}
	return arr
}

func scanStringLine(len int) []string{
	arr := make([]string, len)
	for i:=0; i<len; i++{
		sc.Scan()
		arr[i] = sc.Text()
	}
	return arr
}

func scanIntSplit(len int) []int{
	arr := make([]int, len)
	sc.Scan()
	for i, v := range strings.Split(sc.Text(), " "){
		tmp, err := strconv.Atoi(v)
		if err == nil{
			arr[i] = tmp
		}
	}
	return arr
}

func maxInt(args... int) int{
	sort.Ints(args)
	return args[len(args)-1]
}

func main(){
	buf := make([]byte, 0)
    sc.Buffer(buf, 1000000009)
	var n int 
	fmt.Scan(&n)
	dp := make([][]int, 1003)
	for i:=0; i<1003; i++ {
		dp[i] = make([]int, 1003)
	}
	input_lines := scanStringLine(2*n)
	for i:=0; i<n; i++ {
		S, T := input_lines[2*i], input_lines[2*i+1]
		lenS, lenT := len(S), len(T)
		for i:=1; i<lenS+1; i++ {
			for j:=1; j<lenT+1; j++ {
				if S[i-1] == T[j-1] {
					dp[i][j] = maxInt(dp[i-1][j-1]+1, dp[i-1][j], dp[i][j-1])
				} else {
					dp[i][j] = maxInt(dp[i-1][j], dp[i][j-1])
				}
			}
		}
		fmt.Println(dp[lenS][lenT])
	}
}

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

#define NIL -1
#define INF 1000000001

using namespace std;


int main(){
    int num_dataset;
    char temp[1000];
    scanf("%d",&num_dataset);
    int numSubSeq[1001][1001];
    for(int i = 0;i < 1001;i++) numSubSeq[i][0] = 0; 
    for(int i = 0;i < 1001;i++) numSubSeq[0][i] = 0;

    for(int i = 0;i < num_dataset;i++){
        scanf("%s",temp);
        string str_A = temp;
        int size_A = (int)str_A.size();
        str_A = ' ' + str_A;
  
        scanf("%s",temp);
        string str_B = temp;
        int size_B = (int)str_B.size();
        str_B = ' ' + str_B;
     
        for(int j = 1;j <= size_A;j++){
            for(int k = 1;k <= size_B;k++){    
                if(str_A[j] == str_B[k]){
                    numSubSeq[j][k] = numSubSeq[j-1][k-1] + 1;
                }else{
                    numSubSeq[j][k] = max(numSubSeq[j-1][k],numSubSeq[j][k-1]);
                }
            }
        }
        printf("%d\n",numSubSeq[size_A][size_B]);
    }
    return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;
 
int lcs(string X, string Y) {
int max = 0;
int n = X.size();
int m = Y.size();
int dp[1000+1][1000+1];
 
X = ' '+X;
Y = ' '+Y;
 
for(int i = 1;i <= n; i++)
dp[i][0] = 0;
 
for(int i = 1; i <= m; i++)
dp[0][i] = 0;
 
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= m; j++) {
if(X[i] == Y[j])
dp[i][j] = dp[i-1][j-1]+1;
else if(dp[i-1][j] > dp[i][j-1])
dp[i][j] = dp[i-1][j];
else
dp[i][j] = dp[i][j-1];
 
if(max < dp[i][j])
max = dp[i][j];
}
}
 
return max;
}
 
int main() {
int N;
cin >> N;
 
string X, Y;
for (int i = 0; i < N; i++) {
cin >> X >> Y;
 
cout << lcs(X, Y) << endl;
}
return 0;
}

C++: #include <stdio.h>

int judge(char A[], char B[]){
  int a=0, b=0, sw=0, ans=0;
  int i, j;
  int C[1001][1001];
  
  while(sw == 0){
    if(A[a] != '\0')
      a++;
    else
      sw = 1;
  }
  
  sw = 0;
  
  while(sw == 0){
    if(B[b] != '\0')
      b++;
    else
      sw = 1;
  }
  
  for(i=1; i<a+1; i++)
    C[i][0] = 0;
  for(i=1; i<b+1; i++)
    C[0][i] = 0;
  
  for(i=1; i<a+1; i++){
    for(j=1; j<b+1; j++){
      if(A[i-1] == B[j-1])
        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];
      if(ans < C[i][j])
        ans = C[i][j];
    }
  }
  
  return ans;
}

int main(){
  char A[1000], B[1000];
  int n, i;
  
  scanf("%d", &n);
  
  for(i=0; i<n; i++){
    scanf("%s", A);
    scanf("%s", B);
    printf("%d\n", judge(A, B));
  }
  
  return 0;
}

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

using namespace std;

int lcs(const string & a, const string & b)
{
    vector<vector<int> > dp(a.size(), vector<int>(b.size()));

    for (size_t i = 0; i < dp.size(); ++i) {
        for (size_t j = 0; j < dp[0].size(); ++j) {
            if (a.at(i) == b.at(j)) {
                dp[i][j] = ((i == 0 || j == 0) ? 0 : dp[i - 1][j - 1]) + 1;
            } else {
                dp[i][j] = max(i == 0 ? 0 : dp[i - 1][j],
                               j == 0 ? 0 : dp[i][j - 1]);
            }
        }
    }

    return dp[a.length() - 1][b.length() - 1];
}

int main()
{
    int n;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        string a, b;
        cin >> a >> b;
        cout << lcs(a, b) << endl;
    }

    return 0;
}

C++: #include <iostream> 
#include <cstring> 
using namespace std;
int c[1001][1001];

int lcs(string x, string y)
{
    int maxl = 0;
    int m = x.length(), n = y.length();
 
    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][j-1], c[i-1][j]);
            }
            maxl = max(maxl, c[i][j]);
        } 
    } 
    return maxl;
}

int main()
{
    string x,y;
    int q;
    cin>>q;
    while(q--)
    {
        cin>>x>>y;
        int ans = lcs(x, y);
        cout<<ans<<endl;
    }
    return 0;
}

C++: #include <iostream>
#include <cmath>
#include <vector>
#include <string>
#include <algorithm>
#include <time.h>

using namespace std;

void solve(){
	time_t start, end;

	string A;
	/*for (int i = 0; i < n; i++)*/ cin >> A;
	string B;
	cin >> B;
	int n = A.size(), m = B.size();
	vector<vector<int>> DP(n + 1, vector<int>(m + 1, 0));
	start = clock();
	
	//for (int i = 0; i < n; i++) DP[i][0] = 0;
	//for (int j = 0; j < m; j++) DP[0][j] = 0;

	for (int i = 1; i <= n; i++){
		for (int j = 1; j <= m; j++){
			if (A[i - 1] == B[j - 1]) DP[i][j] = DP[i - 1][j - 1] + 1;
			else DP[i][j] = max(DP[i - 1][j], DP[i][j - 1]);
		}
	}

	end = clock();

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

}

int main(){
	int n;
	cin >> n;
	for (int i = 0; i < n; i++){
		solve();
	}
}

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

int dp[1002][1002];

int main()
{
	for (int i = 0; i < 1002; i++)
	{
		dp[0][i] = 0;
		dp[i][0] = 0;
	}
	int N;
	cin >> N;
	for (int i = 0; i < N; i++)
	{
		string str1, str2;
		cin >> str1 >> str2;
		for (int i = 1; i <= str1.size(); i++)
		{
			for (int j = 1; j <= str2.size(); j++)
			{
				int ans = 0;
				if (str1[i - 1] == str2[j - 1])ans++;
				dp[i][j] = min(max(dp[i - 1][j], dp[i][j - 1]) + ans,min(i,j));
			}
		}
		cout << dp[str1.size()][str2.size()] << endl;
	}
	return 0;
}