Go: package main

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

type Position struct {
	X int
	Y int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}
	for i := 0; i < n; i++ {
		strX := nextText(sc)
		strY := nextText(sc)
		fmt.Println(calcLcs(strX, strY))
	}
}

func calcLcs(strX, strY string) int {
	return lcs(strX, strY, Position{0, 0}, make(map[Position]int))
}

func lcs(strX string, strY string, position Position, memo map[Position]int) int {
	if position.X >= len(strX) || position.Y >= len(strY) {
		return 0
	}
	if v, ok := memo[position]; ok {
		return v
	}
	if strX[position.X] == strY[position.Y] {
		result := lcs(strX, strY, Position{position.X + 1, position.Y + 1}, memo)
		memo[position] = result + 1
		return memo[position]
	} else {
		result1 := lcs(strX, strY, Position{position.X + 1, position.Y}, memo)
		result2 := lcs(strX, strY, Position{position.X, position.Y + 1}, memo)
		var result int
		if result1 > result2 {
			result = result1
		} else {
			result = result2
		}
		memo[position] = result
		return result
	}
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

C++: #include <stdio.h>
#include <string.h>
int main(){
  int k,m,n,i,j,q,c[1001][1001],max=0;
  char X[1000],Y[1000];
  scanf("%d",&q);
  for(i=0;i<q;i++){
    scanf("%s %s",X,Y);
    m=strlen(X);
    n=strlen(Y);
    for(j=m;j>=1;j--){
      X[j]=X[j-1];
    }
    X[0]=' ';
    X[m+1]='\0';
    for(j=n;j>=1;j--){
      Y[j]=Y[j-1];
    }
    Y[0]=' ';
    Y[m+1]='\0';
    for(j=1;j<=m;j++)c[j][0]=0;
    for(j=1;j<=n;j++)c[0][j]=0;
    for(j=1;j<=m;j++){
      for(k=1;k<=n;k++){
	if(X[j]==Y[k])c[j][k]=c[j-1][k-1]+1;
	else{
	  if(c[j][k-1]>c[j-1][k])c[j][k]=c[j][k-1];
	  else c[j][k]=c[j-1][k];
	}
	if(max<c[j][k])max=c[j][k];
      }
    }
    printf("%d\n",max);
    max=0;
  }
  return 0;
}

C++: #include <iostream>

using namespace std;

int lcs(string X, string Y) {
  int memo[1010][1010];
  // 初期化
  for (int i = 0; i < X.size(); i++) {
    memo[i][0] = 0;
  }
  for (int i = 0; i < Y.size(); i++) {
    memo[0][i] = 0;
  }
  int maxl = 0;
  for (int i = 0; i < X.size(); i++) {
    for (int j = 0; j < Y.size(); j++) {
      if (X[i] == Y[j]) {
        memo[i][j] = memo[i-1][j-1] + 1;
      } else {
        memo[i][j] = max(memo[i-1][j], memo[i][j-1]);
      }
      maxl = max(maxl, memo[i][j]);
    }
  }
  return maxl;
}

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

C++: #include <bits/stdc++.h>
using namespace std;

int lcs(string X,string Y){
	int x=X.size(),y=Y.size();
	X = ' '+X;
	Y= ' '+Y;
	int c[1000+10][1000+10];
	for(int i=0;i<1010;i++){
		c[i][0]=0;
		c[0][i]=0;
	}
	for(int i=1;i<=x;i++){
		for(int j=1;j<=y;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]);
			}
		}
	}
	return c[x][y];
}

int main() {
	int n;
	string s1,s2;
	cin>>n;
	for(int i=0;i<n;i++){
	cin>>s1>>s2;
	cout<< lcs(s1,s2)<<endl;
	}
	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<cmath>
#include<string>
using namespace std;
int num;
string X;
string Y;
char c1,c2;
int longest;
int L[1010][1010];
int main()
{
    cin>>num;
    for(int i=0;i<num;i++)
    {
        longest=0;
        cin>>X>>Y;
        for(int m=0;m<=X.size();m++)
            for(int n=0;n<=Y.size();n++)
            {
                if(m<=0||n<=0)
                    L[m][n]=0;
                else if(X[m-1]==Y[n-1])
                    L[m][n]=1+L[m-1][n-1];
                else
                    L[m][n]=max(L[m][n-1],L[m-1][n]);
            }
        for(int a=0;a<=X.size();a++)
            for(int b=0;b<=Y.size();b++)
            {
                if(L[a][b]>longest)
                    longest=L[a][b];
            }
        cout<<longest<<endl;
    }
    return 0;
}

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

static const int N = 100;

int main(){
	int n, p[N+1], m[N+1][N+1];
	cin >> n;
	for (int i=1; i<=n; i++){
		cin >> p[i-1] >> p[i];
	}

	for (int i=1; i<=n; i++) m[i][i] = 0;
	for (int l=2; l <= n; l++){
		for (int i=1; i<=n-l+1; i++){
			int j = i + l - 1;
			m[i][j] = 1 << 21;
			for (int k = i; k<= j - 1; k++){
				m[i][j] = min(m[i][j], m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]);
			}
		}
	}

	cout << m[1][n] << endl;

	return 0;
}

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

int main(){
  int q;
  cin >> q;
  for(int m=0; m<q; m++){
    string wordx, wordy;
    cin >> wordx >> wordy;
    int L[1010][1010]={0};
    
    for(int j=0; j<wordy.size(); j++){
      for(int i=0; i<wordx.size(); i++){
	if(wordx[i]==wordy[j]){
	  L[i+1][j+1] = 1+L[i][j];
	}
	else{
	  L[i+1][j+1] = max(L[i+1][j], L[i][j+1]);
	}
      }
    }
    cout << L[wordx.size()][wordy.size()] << endl;
    
    
  }
}

C++: #include <stdio.h>
#include <string.h>

#define NMAX 1000
#define max(a, b) (a > b ? a : b)

int c[NMAX + 10][NMAX + 10]; // 1-origin

int lcs(char *x, char *y) {
    int m = strlen(x);
    int n = strlen(y);
    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= n; j++) {
            if (x[i - 1] == y[j - 1]) // 0-origin
                c[i][j] = 1 + c[i - 1][j - 1];
            else
                c[i][j] = max(c[i - 1][j], c[i][j - 1]);
        }
    }
    return c[m][n];
}

int main() {
    // init
    for (int i = 1; i <= NMAX; i++) {
        c[0][i] = 0;
        c[i][0] = 0;
    }
    int q;
    scanf("%d", &q);
    char x[NMAX + 10], y[NMAX + 10]; // 0-origin
    for (int i = 0; i < q; i++) {
        scanf("%s %s", x, y);
        printf("%d\n", lcs(x, y));
    }
    return 0;
}

C++: /*
 * ALDS1_10_C.cpp
 *
 *  Created on: May 5, 2018
 *      Author: 13743
 */

#include<cstdio>
#include<cstring>
#include<algorithm>

int dp[1001][1001];
bool dpR[1001][1001];

int lcm(char* X, char* Y, int nx, int ny) {
	dp[1][1] = (X[0] == Y[0]);
	for(int i=1; i<=nx; i++) {
		for(int j=1; j<=ny; j++) {
			dp[i][j] = (X[i-1]==Y[j-1]) + dp[i-1][j-1];
			dp[i][j] = std::max(dp[i-1][j], dp[i][j]);
			dp[i][j] = std::max(dp[i][j-1], dp[i][j]);
		}
	}
	return dp[nx][ny];
}

int lcmRec(char* X, char* Y, int nx, int ny) {
	if(nx <=0 || ny <= 0) return 0;
	if(!dpR[nx][ny]) {
		dpR[nx][ny] = 1;
		dp[nx][ny] = lcmRec(X, Y, nx-1, ny-1) + (X[nx-1]==Y[ny-1]);
		dp[nx][ny] = std::max(lcmRec(X, Y, nx-1, ny), dp[nx][ny]);
		dp[nx][ny] = std::max(lcmRec(X, Y, nx, ny-1), dp[nx][ny]);
	}
	return dp[nx][ny];
}

int main() {
	int q;
	scanf("%d", &q);
	char X[1001];
	char Y[1001];
	while(q--) {
		for(int i=0; i<1001; i++) {
			for(int j=0; j<1001; j++) {
				dpR[i][j] = dp[i][j] = 0;
			}
		}
		scanf("%s", X);
		scanf("%s", Y);
		int nx = (int)strlen(X);
		int ny = (int)strlen(Y);
		printf("%d\n", lcm(X, Y, nx, ny));
		//printf("%d\n", lcmRec(X, Y, nx, ny));
	}
}