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

using namespace std;

static const int N = 1000;

static int lcs(string& s1, string& s2) {
    int table[N + 1][N + 1];

    int m = s1.size();
    int n = s2.size();

    int max_len = 0;

    s1 = ' ' + s1;
    s2 = ' ' + s2;

    for (int i = 0; i <= m; i++) table[i][0] = 0;
    for (int j = 0; j <= m; j++) table[0][j] = 0;

    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= n; j++) {
            if (s1[i] == s2[j]) {
                table[i][j] = table[i - 1][j - 1] + 1;
            } else {
                table[i][j] = max(table[i - 1][j], table[i][j - 1]);
            }

            max_len = max(table[i][j], max_len);
        }
    }

    return max_len;
}

int main() {
    int n;

    cin >> n;

    for (int i = 0; i < n; i++) {
        string s1, s2;

        cin >> s1 >> s2;

        cout << lcs(s1, s2) << endl;
    }

    return 0;
}

C++: #include<iostream>
#include<vector>
#include<string>
#include<algorithm>
using namespace std;
string s1,s2;
int memo[1001][1001];

int solve(int l1,int l2){
  if(l1 < 0 or l2 < 0)return 0;
  if(memo[l1][l2] >= 0)return memo[l1][l2];
  //cout << s1[l1] << s2[l2] << endl;
  if(s1[l1] == s2[l2]){
    return memo[l1][l2] = solve(l1 - 1,l2 - 1) + 1;
  }
  return memo[l1][l2] = max(solve(l1,l2-1), solve(l1-1,l2));
}
int main(){
  int n;
  cin >> n;
  for(int i = 0;i < n;i++){
    fill(memo[0],memo[1001],-1);
    cin >> s1 ;
    cin >> s2;
    cout << solve(s1.length(),s2.length()) - 1 << endl;
  }
}

C++: #include <iostream>
#include <string>
#include <algorithm>
#include <functional>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <bitset>
#include <map>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
using namespace std;
typedef long long ll;
typedef pair<int,int> pint;
typedef vector<int> vint;
typedef vector<pint> vpint;
#define mp make_pair
#define fi first
#define se second
#define all(v) (v).begin(),(v).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
int dx[4] = {1, 0, 0, -1};
int dy[4] = {0, 1, -1, 0};

int slove(string X, string Y){
	int dp[1000][1000];//dp[X?????????][Y?????????] = LCS
	int sizex = X.size();
	int sizey = Y.size();

	//???????????????????????????????????????????????????0????????????????????\?????????
	X = ' ' + X;
	Y = ' ' + Y;

	reps(i, 1, sizex + 1) dp[i][0] = 0;//?????????????????????0??????dp???0
	reps(i, 1, sizey + 1) dp[0][i] = 0;//?????????????????????0??????dp???0

	int ans = 0;//????°??????????
	reps(i, 1, sizex + 1){
		reps(j, 1, sizey + 1){
			if(X[i] == Y[j]) dp[i][j] = dp[i - 1][j - 1] + 1;
			else if(X[i] != Y[j]) dp[i][j] = max(dp[i][j - 1], dp[i - 1][j]);

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

int main(void){
	int n; cin >> n;
	string s1, s2;
	rep(i, n){
		cin >> s1 >> s2;
		printf("%d\n", slove(s1, s2));
	}
	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=0; i<=n; i++) c[i][0] = 0;
	for (int j=0; j<=m; j++) c[0][j] = 0;

	for (int i = 1; i <= n; i++){
		for (int j = 1; j <= m; 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 s1, s2;
	int q;
	cin >> q;
	for (int i=0; i<q;i++){
		cin >> s1 >> s2;
		cout << lcs(s1, s2) << endl;
	}
	return 0;

}

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

int LCS(string a,string b){
    int n1=a.size(),n2=b.size();
    int DP[n1+1][n2+1];
    DP[0][0]=0;
    rep(i,n1)DP[i+1][0]=0;
    rep(i,n2)DP[0][i+1]=0;
    rep(i,n1){
        rep(j,n2){
            if(a[i]==b[j])DP[i+1][j+1]=1+DP[i][j];
            else DP[i+1][j+1]=max(DP[i][j+1],DP[i+1][j]);
        }
    }
    return DP[n1][n2];
}

int main(){
    int q;cin>>q;
    string s,t;
    rep(i,q){
        cin>>s>>t;
        int ans=LCS(s,t);
        printf("%d\n",ans);
    }
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cassert>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define rep(i,n) FOR(i,0,n)
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define vint vector<int>
#define vdouble vector<double>
#define vstring vector<string>
using namespace std;

#include<map>
#include<set>
#include<queue>

typedef long long ll;
typedef unsigned long long ull;

const int MAX_N = 1000000;
const int MAX_L = 1000;
int q;
string data[MAX_N][2];
ll mem[MAX_L][MAX_L];

ll eval(string s1, string s2, int i, int j){
	int ii = i - 1;
	int jj = j - 1;
	if (ii == -1 || jj == -1) return 0;
	if (s1[ii] == s2[jj]) return mem[i - 1][j - 1] + 1;
	if (s1[ii] != s2[jj]) return max(mem[i - 1][j], mem[i][j - 1]);
	throw "exception";
}

ll solve(string s1, string s2){

	int L1 = s1.size();
	int L2 = s2.size();
	rep(i, L1 + 1){
		rep(j, L2 + 1)
		{
			mem[i][j] = eval(s1, s2, i, j);
		}
	}

	return mem[L1][L2];
}

int main() {

	cin >> q;
	rep(i, q){
		cin >> data[i][0];
		cin >> data[i][1];
	}

	rep(i, q){
		cout << solve(data[i][0], data[i][1]) << endl;
	}
}