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 <stdio.h>
#include <iostream>
#include <algorithm>

using namespace std;

short checkTable[1001][1001];

int tmp_max=0;


void calc(int index,char pattern[],char to_search[],int to_search_length){

	for(int i=to_search_length-1;i>=0;i--){
		if(to_search[i]==pattern[index]){
			checkTable[index][i]=1;
			if(pattern[index+1]!='\0' && i < to_search_length-1){
				checkTable[index][i] = checkTable[index+1][i+1] + checkTable[index][i];
			}
		}else{
			if(i != to_search_length-1){
				if(pattern[index+1] != '\0'){
					checkTable[index][i]=(checkTable[index+1][i]>checkTable[index][i+1])
							?checkTable[index+1][i]:checkTable[index][i+1];

				}else{
					checkTable[index][i]=(checkTable[index][i+1]>0)?checkTable[index][i+1]:0;
				}
			}else{
				if(pattern[index+1] != '\0'){
					checkTable[index][i]=(checkTable[index+1][i]>0)?checkTable[index+1][i]:0;
				}else{
					checkTable[index][i] = 0;
				}
			}
		}
		tmp_max = (tmp_max >= checkTable[index][i])?tmp_max:checkTable[index][i];
	}
}

int main(){

	int q,left_length,right_length;
	char left[1001],right[1001];

	scanf("%d",&q);

	for(int i=0;i<q;i++){
		left_length=0;
		right_length=0;
		scanf("%s %s",left,right);
		for(int k=0;left[k]!='\0';k++)left_length++;
		for(int k=0;right[k]!='\0';k++)right_length++;

		if(right_length>=left_length){

			for(int k=left_length-1;k>=0;k--)calc(k,left,right,right_length);
		}else{

			for(int k=right_length-1;k>=0;k--)calc(k,right,left,left_length);
		}
		printf("%d\n",tmp_max);
		tmp_max=0;
	}

    return 0;
}

C++: #include <iostream>
#define MAX 1010

int C[MAX][MAX];

int main() {
  int n;
  std::cin >> n;
  int answers[160];

  for(int m=0; m<n; ++m) {
    std::string X;
    std::string Y;
    std::cin >> X;
    std::cin >> Y;

    // initialize
    for(int k=0; k<MAX; ++k) {
      for(int j=0; j<MAX; ++j) C[k][j] = 0;
    }

    // lcs
    int xlen = X.size();
    int ylen = Y.size();

    for(int i=1; i<=xlen; ++i) {
      for(int j=1; j<=ylen; ++j) {
        if(X[i] == Y[j]) {
          C[i][j] = C[i-1][j-1] + 1;
        } else {
          C[i][j] = std::max(C[i-1][j], C[i][j-1]);
        }
      }
    }

    answers[m] = C[xlen][ylen];
  }

  for(int h=0; h<n; ++h) {
    std::cout << answers[h] << std::endl;
  }
}

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 = 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 <iostream>
#include <string>
using namespace std;

int lcs(string X, string Y) {
  int dp[1000 + 1][1000 + 1];
  int max = 0;
  int m = X.size();
  int n = Y.size();
  X = ' ' + X;
  Y = ' ' + Y;

  for (int i = 1; i <= m; i++)
    dp[i][0] = 0;

  for (int i = 1; i <= n; i++)
    dp[0][i] = 0;

  for (int i = 1; i <= m; i++) {
    for (int j = 1; j <= n; 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];

      max = (max < dp[i][j]) ? dp[i][j] : max;
    }
  }

  return max;
}

int main(int argc, char const *argv[]) {
  int N;
  cin >> N;

  for (int i = 0; i < N; i++) {
    string X, Y;
    cin >> X >> Y;

    cout << lcs(X, Y) << endl;
  }

  return 0;
}

C++: #include <iostream>
#define MAX 1010

int C[MAX][MAX];

int main() {
  int n;
  std::cin >> n;
  int answers[160];

  for(int m=0; m<n; ++m) {
    std::string X;
    std::string Y;
    std::cin >> X;
    std::cin >> Y;

    // initialize
    for(int k=0; k<MAX; ++k) {
      for(int p=0; p<MAX; ++p) C[k][p] = 0;
    }

    // lcs
    int xlen = X.size();
    int ylen = Y.size();

    X = ' ' + X;
    Y = ' ' + Y;

    for(int i=1; i<=xlen; ++i) {
      for(int j=1; j<=ylen; ++j) {
        if(X[i] == Y[j]) {
          C[i][j] = C[i-1][j-1] + 1;
        } else {
          C[i][j] = std::max(C[i-1][j], C[i][j-1]);
          
        }
      }
    }

    answers[m] = C[xlen][ylen];
  }

  for(int h=0; h<n; ++h) {
    std::cout << answers[h] << std::endl;
  }
}

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

constexpr 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;

   //c[i][j]のためにX[0],Y[0]に空白を挿入
   X=' '+X;
   Y=' '+Y;
   for(int i=1; i<m+1; i++) c[i][0]=0;
   for(int j=1; j<n+1; j++) c[0][j]=0;

   for(int i=1; i<m+1; i++){
      for(int j=1; j<n+1; 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 x, y;
   int n; cin >> n;
   for(int i=0; i<n; i++){
      cin >> x;
      cin >> y;
      cout << lcs(x, y) << endl;
   }

   return 0;
}