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<iostream>
#include<string>
#include<cstdlib>
#include<algorithm>

int main(){
  int n;
  std::cin>>n;
  int B[1500]={0};
  for(int k=0;k<n;k++){
    std::string str1;
    std::string str2;
    std::cin>>str1;
    std::cin>>str2;
    int A[1000][1000]={0};
    /*初期化？*/
    for(int i=0;i<str1.size();i++){
      for(int j=0;j<str2.size();j++){
	if(j==0){
	  if(str1[i]==str2[j]){
	    A[i][j]=1;
	  }
	  if(i>0){
	    A[i][j]=std::max(A[i][j],A[i-1][j]);
	  }
	}
	if(i==0){
	  if(str1[i]==str2[j]){
	    A[i][j]=1;
	  }
	  if(i>0){
	    A[i][j]=std::max(A[i][j],A[i][j-1]);
	  }
	}
      }
    }
    for(int i=1;i<str1.size();i++){
      for(int j=1;j<str2.size();j++){
	if(str1[i]==str2[j]){
	  A[i][j]=A[i-1][j-1]+1;
	}else{
	  A[i][j]=std::max(A[i-1][j],A[i][j-1]);
	}
      }
    }
    B[k]=A[str1.size()-1][str2.size()-1];
  }
  for(int i=0;i<n;i++){
    std::cout<<B[i]<<"\n";
  }
  return 0;
}

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

#define MAX 1000

int lcs(string X, string Y) {
    int c[MAX+1][MAX+1];
    int m = X.size();
    int n = Y.size();
    int i, j;
    int maxlen = 0;
    X = " " + X;
    Y = " " + Y;

    for (i = 1 ; i <= m ; i++ ) c[i][0] = 0;
    for (j = 1 ; j <= n ; j++ ) c[0][j] = 0;

    for(i = 1 ; i <= m ; i++ ) {
        for(j = 1 ; j <= n ; j++ ) {
            if (X[i] == Y[j]) {
                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];
            }
            maxlen = max(maxlen, c[i][j]);
        }
    }
    return maxlen;
}

int main (void) {
    int N, i;
    string x, y;
    int l[MAX+1];    

    cin >> N;

    for(i = 0 ; i < N ; i++) {
        cin >> x;
        cin >> y;
        l[i] = lcs(x,y);
    }

    for(i = 0 ; i < N ; i++) {
        printf("%d\n", l[i]);
    }

    return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<string>
#include<algorithm>
#include<vector>
#include<cmath>
#include<map>
#include<bitset>
#include<queue>
#include<set>
using namespace std;
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define rep(i,n) FOR(i,0,n)
#define MAX 1002
typedef long long ll;

int make(string a, string b){

	int dp[MAX][MAX] = {};
	
	a = ' ' + a;
	b = ' ' + b;

	int len_a = a.size();
	int len_b = b.size();

	FOR(i,1,len_a){
	FOR(j,1,len_b){
	if (a[i]==b[j]) dp[i][j] = 1 + dp[i-1][j-1];
	else dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
	}
	}

	return dp[len_a-1][len_b-1];
} 	
	

int main(){
	int q;
	cin >> q;
	string str1,str2;
	rep(i,q){
	cin >> str1>>str2;
	cout << make(str1,str2) << endl;
	}
	return 0;
}

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

using namespace std;

string s, t;

vector<vector<int>> memo(2000, vector<int>(2000,-1));

//s???i??????????????§???t???j??????????????§?????£?????¨??????LCS
int solve(int i, int j) {
	if (memo[i][j] != -1)return memo[i][j];

	if (i == 0 && j == 0)return (s[0] == t[0]);
	if (i == 0)return memo[i][j] = (bool)(solve(i, j - 1) + (s[i] == t[j]));
	if (j == 0)return memo[i][j] = (bool)(solve(i - 1, j) + (s[i] == t[j]));
	if (s[i] == t[j]) return solve(i - 1, j - 1) + 1;
	return memo[i][j] = max(solve(i - 1, j), solve(i, j - 1));
}

int main() {
	int n;
	cin >> n;
	while (n--) {
		cin >> s >> t;
		memo = vector<vector<int>>(2000, vector<int>(2000,-1));
		cout << solve(s.size() - 1, t.size() - 1) << endl;
	}
}

C++: #include <iostream>
#include <algorithm>
#include <stack>
#include <string>
#include <queue>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <vector>
#include <list>
#include <string.h>
#define _USE_MATH_DEFINES
#include <math.h>
#include <map>
#define INFTY (1<<30)
#define MAX 100000000

using namespace std;

int lcs(string x, string y) {
	int m = x.size(), n = y.size();
	int c[1000+1][1000+1];
	x = ' ' + x; y = ' ' + y;
	for( int i = 0; i <= m; i++) c[i][0] = 0;
	for( int j = 0; j <= n; j++) c[0][j] = 0;
	for( int i = 1; i <= m; i++) {
		for( int j = 0; j < n; j++) {
			if(x[i] == y[j]) c[i][j] = c[i-1][j-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];
		}
	}
	return c[m][n];
}

int main(){
	int q;
	for( int i = 0; i < q; i++) {
		string s, t;
		cin >> s >> t;
		cout << lcs(s, t) <<endl;
	}

	return 0;
}

C++: #include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
using namespace std;
const int N = 1010;
char x[N],y[N];
int c[N][N];
int lcs(char x[],char y[]){

    int lenx = strlen(x+1);
    int leny = strlen(y+1);

    for (int i=0; i<=lenx; i++) {
        c[i][0] = 0;
    }
    for(int j=1;j<=leny;j++){
        c[0][j] = 0;
        
    }

    for(int i=1;i<lenx;i++){
        for(int j=1;j<leny;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]);
        }
    }
    return c[lenx][leny];
}
int main(){
    int q;
    scanf("%d",&q);
    for (int i=0; i<q; i++) {
        gets(x+1);
        gets(y+1);
        cout<<lcs(x, y)<<endl;
    }
    return 0;
}

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

int main(){
  int dp[1000][1000]={0};
  int n,m=0;
  int ans[150];
  std::string str1,str2;
  std::cin>>n;
  for(int k=0;k<n;k++){
    std::cin>>str1>>str2;
    for(int i=1;i<=str1.size();i++){
      for(int j=1;j<=str2.size();j++){
	if(str1[i-1]==str2[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]);
	}
      }
    }
    ans[m]=dp[str1.size()][str2.size()];
    m++;
  }
  for(int i=0;i<m;i++){
    std::cout<<ans[i]<<"\n";
  }
  return 0;
}