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] = dp[i-1][j-1]+1
				} else if S[i-1] != T[j-1] && dp[i-1][j] > dp[i][j-1] {
					dp[i][j] = dp[i-1][j]
				} else {
					dp[i][j] = dp[i][j-1]
				}
				// 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<algorithm>
using namespace std;
int dp[111][111];
int lcs(string x,string y){
	for(int i=0;i<12321;i++)dp[i/111][i%111]=0;
	for(int i=0;i<=y.size();i++){
		for(int j=0;j<=x.size();j++){
			if(i==0 || j==0){dp[i][j]=0;}
			else if(x[j]==y[i]){dp[i][j]=dp[i-1][j-1]+1;}
			else{dp[i][j]=max(dp[i][j-1],dp[i-1][j]);}
		}
	}
	int MAXN=0;
	for(int i=0;i<=y.size();i++){
		for(int j=0;j<=x.size();j++){
			MAXN=max(MAXN,dp[i][j]);
		}
	}
	return MAXN;
}
int main(){
	int n;string S,T;
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>S>>T;cout<<lcs(S,T)<<endl;
	}
	return 0;
}

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;
}