Go: package main

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

func max(x, y int) int {
	if x < y {
		return y
	} else {
		return x
	}
}

/*********************************************************************
長さmの列X_(m)と長さnの列Y_(n)の最長共通部分列LCSは、
	(1)X[m] == Y[n]ならば、X_(m-1)とY_(n-1)のLCSにX[m]を繋げたもの
	(2)X[m] != Y[n]ならば、X_(m-1)とY_(n)のLCSもしくはX_(m)とY_(n-1)のLCS
	のいずれかのうち長い方

c[m+1][n+1]：c[i][j]にX_(i)とY_(j)のLCSの長さを格納する二次元配列
*********************************************************************/

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Scan()
	n, _ := strconv.Atoi(scanner.Text())
	for i := 0; i < n; i++ {
		scanner.Scan()
		s1 := scanner.Text()
		scanner.Scan()
		s2 := scanner.Text()
		s1, s2 = " " + s1 , " " + s2
		c := make([][]int, len(s1))
		for i := range c {
			c[i] = make([]int, len(s2))
		}

		LCS := 0

		for i := 1; i < len(s1); i++ {
			for j := 1; j < len(s2); j++ {
				if s1[i] == s2[j] {
					c[i][j] = c[i-1][j-1] + 1
				} else {
					c[i][j] = max(c[i-1][j], c[i][j-1])
				}
				LCS = max(LCS, c[i][j])
			}
		}
		fmt.Println(LCS)
	}
}

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

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

int main(void){
  char x[1005]={0};
  char y[1005]={0};
  int set=0;
  int dp[1005][1005]={0};
  /*dp[i][j]は、xのi文字目とyのj文字目での最長部分列*/
  scanf("%d",&set);
  int p=0,i=0,j=0;;
  for(p=0;p<set;p++){
    scanf("%s%s",x,y);
    int xl,yl;
    xl=strlen(x);yl=strlen(y);
    int ma,mb,mc;
    for(i=1;i<xl+1;i++){
      for(j=1;j<yl+1;j++){
	ma=dp[i][j-1];
	mb=dp[i-1][j];
	mc=dp[i-1][j-1];
	if(x[i-1]==y[j-1])mc++;
	//dp[i][j]= ma<mb ? (mb<mc ? mc : mb) : ma;
	dp[i][j]= max(ma,max(mb,mc));
      }
    }
    printf("%d\n",dp[xl][yl]);
  }
  return 0;
}

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

string X;
string Y;

int calc(int x_s, int x, int y, int length){
    if (X[x] == '\0') return length;
    int y_ = Y.find(X[x], y);
    if (y_ == string::npos) {
        if ((Y[y+1] == '\0')) {
            return max(length, calc(x_s + 1, x_s + 1, 0, 0));
        }
        return max(length, calc(x_s, x, y + 1, length));
    }
    return calc(x_s, x + 1, y_ + 1, length + 1);
}

int main(){
    int q;
    cin >> q;
    for (int i = 0; i < q; i++) {
        cin >> X;
        cin >> Y;
        cout << calc(0, 0, 0, 0) << endl;
    }

    return 0;
}

C++: #include <iostream>
#include <string>
#include <utility>
using namespace std;
#define MAXQ 150
#define MAXL 1000

int main(){
    int n; cin >> n;
    pair<string, string> pairs[MAXQ];
    for(int i=0; i<n; ++i){
        cin >> pairs[i].first >> pairs[i].second;
    }
    
    for(int i=0; i<n; ++i){
        string str1, str2;
        str1 = pairs[i].first;
        str2 = pairs[i].second;
        int dp[MAXL][MAXL];
        for(int r=0; r<=str1.size(); ++r){
            dp[r][0] = 0;
        }
        for(int c=0; c<=str2.size(); ++c){
            dp[0][c] = 0;
        }
        for(int r=1; r<=str1.size(); ++r){
            for(int c=1; c<=str2.size(); ++c){
                int d = 0;
                if (str1[r] == str2[c]) d++;
                dp[r][c] = max(dp[r-1][c-1]+d, max(dp[r-1][c], dp[r][c-1]));
            }
        }
        cout << dp[str1.size()][str2.size()] << endl;
    }
}

C++: #include "bits/stdc++.h"
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;

using ll = long long;

int main() {
    //dp[i][j] Xのi文字目までとYのj文字目までのLCS
    int q;
    cin >> q;
    rep(i, q) {
        string X, Y;
        cin >> X >> Y;
        int m = X.size(), n = Y.size();
        vector<vector<int>> dp(m + 1, vector<int>(n + 1, 0));
        rep(j, m) {
            rep(k, n) {
                if (X[j] == Y[k]) {
                    dp[j + 1][k + 1] = dp[j][k] + 1;
                } else {
                    dp[j + 1][k + 1] = max(dp[j][k + 1], dp[j + 1][k]);
                }
            }
        }
        cout << dp[m][n] << "\n";
    }
}

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

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

        int DP[1024][1024] = {};

        for(int i=0;i<=(int)X.size();++i){
            for(int j=0;j<=(int)Y.size();++j){
                if(X[i] == Y[j]){ // 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]);
                }
            }
        }
        cout << DP[(int)X.size()][(int)Y.size()] << endl;
    }
}

C++: #include <bits/stdc++.h>
#define rep(i,n) for(int i=0; i<(n); i++)
#define FOR(i,a,n) for(int i=(a); i<(n); i++)
#define all(v) v.begin(), v.end()
#define fi first
#define se second
using namespace std;
using ll = long long;
using P = pair<int ,int>;
const int INF = 1e9;
const int MOD = 1e9+7;

void print() { cout << endl; }
template <class Head, class... Tail> void print(Head&& head, Tail&&... tail) { cout << head << ((sizeof...(tail)!=0)?" ":""); print(forward<Tail>(tail)...); }
template <class T> void print(vector<T> &vec) { for (auto& a : vec) { cout << a << ((&a!=&vec.back())?" ":""); } cout << endl; }
template <class T> void print(vector<vector<T>> &df) { for (auto& vec : df) { print(vec); } }

int dp[1010][1010];

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n; cin >> n;
    rep(_, n) {
        string s, t; cin >> s >> t;
        memset(dp, 0, sizeof(dp));
        int n = s.length(), m = t.length();
        rep(i, n) rep(j, m) {
            char a = s[i], b = t[j];
            if (a==b) dp[i+1][j+1] = dp[i][j]+1;
            else dp[i+1][j+1] = max(dp[i+1][j], dp[i][j+1]);
        }

        cout << dp[n][m] << 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.xize();
	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) << end1;
	}
	
	return 0;
}

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>
#include <algorithm>
#include <vector>

using namespace std;
static const int N = 1000;

int lenCommon(string s1, string s2)
{
	int len = max(int(s1.size()), int(s2.size()));
	vector<vector<int>> dp(N+1, vector<int>(N+1, 0));

	s1 = " " + s1;
	s2 = " " + s2;

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

	int ret = 0;
	for (int i = 1; i <= len; ++i)
	{
		for (int j = 1; j <= len; ++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]);

			ret = max(ret, dp[i][j]);
		}
	}
	return ret;
}

int main()
{
	string s1, s2;
	int num; cin >> num;
	for (int i = 0; i < num; ++i)
	{
		cin >> s1 >> s2;
 		int res = lenCommon(s1, s2);
		cout << res << endl;
	}
}