Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)
	for i := 0; i < n; i++ {
		x := getNextString(scanner)
		y := getNextString(scanner)

		fmt.Fprintln(writer, lcs(x, y))
	}

	writer.Flush()
}

func lcs(x, y string) int {
	lx := len(x)
	ly := len(y)
	dp := make([][]int, lx+1)
	for i := 0; i <= lx; i++ {
		dp[i] = make([]int, ly+1)
	}
	for i := 0; i < lx; i++ {
		for ii := 0; ii < ly; ii++ {
			if x[i] == y[ii] {
				dp[i+1][ii+1] = dp[i][ii] + 1
				continue
			}
			dp[i+1][ii+1] = dp[i][ii+1]
			if dp[i+1][ii] > dp[i+1][ii+1] {
				dp[i+1][ii+1] = dp[i+1][ii]
			}
		}
	}
	return dp[lx][ly]
}

C++: #include<stdio.h>
#include<string.h>
#include<iostream>
#include<algorithm>
using namespace std;
int p[1001][1001]={0};
int main(){
int i,j,q,e,l,z,m,u,n;
char s[2001],c[2001];
cin>>q;
for(e=0;e<q;e++){
scanf("%s %s",s,c);
l=strlen(s);
z=strlen(c);

for(i=0;i<=l;i++){
	for(j=0;j<=z;j++){
		p[i][j]=0;
	}
}
for(i=1;i<=z;i++){
	for(j=1;j<=l;j++){
		if(c[i-1]==s[j-1])p[j][i]=p[j-1][i-1]+1;
		else p[j][i]=max(p[j-1][i],p[j][i-1]);
	}
}
cout<<p[l][z]<<endl;
}
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[1001][1001];

 int m = X.size();
 int n = Y.size();
 int maxl = 0;
 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 = 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][j-1];
    } else {
      c[i][j] = c[i-1][j];
   }
  if (maxl < c[i][j]) {
      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++: #if 0
?????????X[0]???????????????????????\???????????¨??§???X[1],Y[1]???????????????????????????????????????
#endif

#include <iostream>
#include <string>
using namespace std;

int main(){
	int q;
	cin >> q;
	for(int a=0;a<q;++a){
		string X,Y;
		int L[1000][1000];
		cin >> X >> Y;
		for(int i=0;i<1000;++i) //???????????\????????????L????????????
			for(int j=0;j<1000;++j)
				L[i][j]=0;
	
		for(int j=1;j<X.size()+1;++j)
			for(int k=1;k<Y.size()+1;++k){
				if(X[j-1]==Y[k-1])
					L[j][k]=1+L[j-1][k-1];
				else
					L[j][k]=max(L[j-1][k],L[j][k-1]);
			}
		cout << L[X.size()][Y.size()] << endl;
	}
}

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

using namespace std;

#if 0
http://judge.u-aizu.ac.jp/onlinejudge/review.jsp?rid=2065462#1
#endif

int n;
string a, b;
string x[10000], y[10000];




int main(){
  cin >> n;
  while(n != 0){
    n = n -1;
    int longest[1000][1000];
    cin >> a;
    cin >> b;
    a = ' ' + a;
    b = ' ' + b;
    int mm = 0;
    /*
    for(int i = 0; i < a.size(); ++i){
      for(int j = 0; j < b.size(); ++j){
        
        x[i] = a;
        y[j] = b;
      }
    }
    */
   //longest[0][0] =0;
   for(int i = 1; i <= a.size(); ++i){
     longest[i][0] = 0;
    }
   for(int j = 1; j <= b.size(); ++j){
     longest[0][j] = 0;
   }
    for(int i = 1; i <= a.size(); ++i){
      for(int j = 1; j <= b.size(); ++j){
        
        /*
        if(i <= 0 || j <=0){
          longest[i][j] = 0;
        }
        */
        if(a[i] == b[j]){
          longest[i][j] = 1 + longest[i-1][j - 1];
        }
        else{
          longest[i][j] = max(longest[i][j-1], longest[i-1][j]);
        }
        mm = max(mm, longest[i-1][j-1]);
      }
    }
    //cout << a[1] << endl;
    cout << mm << endl;
  }
}