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<bits/stdc++.h>
using namespace std;
static const int N=1001;
int lcs(string X,string Y){
  int c[N+1][N+1];
  int m=X.length();
  int n=Y.length();

  int max1=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]);
      }
      max1=max(max1,c[i][j]);
    }
  }
  return max1;
}

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 <cstdio>
#include <vector>
using namespace std;

#define MAXX 1024

int min(int a, int b){
	return a > b ? b : a;
}
int max(int a, int b){
	return a < b ? b : a;
}

int LCS(char* a, char* b){
	int al = 0, bl = 0;
	for (int i = 0; i < MAXX; i++){
		if (a[i] == '\0') al = i;
		if (b[i] == '\0') bl = i;
		if (al != 0 && bl != 0) break;
	}
	vector< vector<int> > table(al, vector<int>(bl, 0));
	for (int i = 0; i < al + bl - 1; i++){
		for (int j = max(i - al + 1, 0); j <= min(bl - 1, i); j++){
			if (a[i - j] == b[j]){
				if (i - j == 0 || j == 0){
					table[i - j][j] = 1;
				}
				else{
					table[i - j][j] = table[i - j - 1][j - 1] + 1;
				}
			}
			else{
				if (i - j == 0 && j == 0){
					table[i - j][j] = 0;
				}
				else if (i - j == 0 && j != 0){
					table[i - j][j] = table[i - j][j - 1];
				}
				else if (i - j != 0 && j == 0){
					table[i - j][j] = table[i - j - 1][j];
				}
				else{
					table[i - j][j] = max(table[i - j - 1][j], table[i - j][j - 1]);
				}
			}
		}
	}
	return table[al-1][bl-1];
}

int main(){
	int n, dum;
	scanf("%d", &n);
	char a[MAXX], b[MAXX];
	for (int i = 0; i < n; i++){
		scanf("%s", &a);
		scanf("%s", &b);
		printf("%d\n", LCS(a, b));
	}

	return 0;
}

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

int lcs(string str1, string str2){
  int C[1001][1001];
  int max = 0;

  str1 = ' ' + str1;
  str2 = ' ' + str2;

  for(int i = 1 ; i <= str1.size() ; i++) C[i][0] = 0;
  for(int j = 1 ; j <= str2.size() ; j++) C[0][j] = 0;

  for(int i = 1 ; i <= str1.size() ; i++){
    for(int j = 1 ; j <= str2.size() ; j++){
      if(str1[i] == str2[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 - 1][j];
	else if(C[i][j -1] > C[i - 1][j]) C[i][j] = C[i][j - 1];
      }

      if(max > C[i][j]) max = max;
      else if(C[i][j] > max) max = C[i][j];

    }
  }

  return max;
}

int main(){
  string str1, str2;
  int n;

  cin >> n;

  for(int i = 0 ; i < n ; i++){
    cin >> str1 >> str2;
    cout << lcs(str1, str2)-1 << endl;
  }

  return 0;
}

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

#define MAX 1000

int lcs(string X, string Y) {
    int c[MAX+1][MAX+1];
    int m = X.size();
    int n = Y.size();
    int i, j;
    int maxlen = 0;
    X = " " + X;
    Y = " " + Y;

    for (i = 1 ; i <= m ; i++ ) c[i][0] = 0;
    for (j = 1 ; j <= n ; j++ ) c[0][j] = 0;

    for(i = 1 ; i <= m ; i++ ) {
        for(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][j-1], c[i-1][j]);
            }
            maxlen = max(maxlen, c[i][j]);
        }
    }
    return maxlen;
}

int main (void) {
    int N, i;
    string x, y;

    cin >> N;

    for(i = 0 ; i < N ; i++) {
        cin >> x;
        cin >> y;
        printf("%d\n", lcs(x,y));
    }

    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;    // X[0]に空白を挿入
    Y = ' ' + Y;    // Y[0]に空白を挿入
    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 {
                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;
}