Go: package main

/*
最長共通部分列
*/

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"os"
	"strconv"
	"strings"
)

func larger(l, r int) int {
	if l > r {
		return l
	}
	return r
}

var memo [1001][1001]int

func countLCS(x, y string) int {
	x = " " + x
	y = " " + y
	max := 0
	for xi := 1; xi < len(x); xi++ {
		for yi := 1; yi < len(y); yi++ {
			if x[xi] == y[yi] {
				memo[xi][yi] = memo[xi-1][yi-1] + 1
			} else {
				memo[xi][yi] = larger(memo[xi-1][yi], memo[xi][yi-1])
			}
			max = larger(max, memo[xi][yi])
		}
	}
	return max
}

func main() {
	scanner := makeScanner(1024)
	q := eGetInt(scanner)
	for i := 0; i < q; i++ {
		x := eGetLine(scanner)
		y := eGetLine(scanner)
		fmt.Println(countLCS(x, y))
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

type ints []int

func (s ints) String() string {
	var buf bytes.Buffer
	buf.WriteString("[")
	sep := ""
	for _, v := range s {
		buf.WriteString(fmt.Sprintf("%s%d", sep, v))
		sep = ", "
	}
	buf.WriteString("]")
	return buf.String()
}

func reverse(a ints) ints {
	r := make(ints, len(a))
	for i := 0; i < len(a); i++ {
		r[i] = a[len(a)-1-i]
	}
	return r
}
func max(a ints) (int, bool) {
	if len(a) == 0 {
		return 0, false
	}
	m := a[0]
	for _, e := range a {
		if e > m {
			m = e
		}
	}
	return m, true
}
func min(a []int) int {
	m := a[0]
	for _, v := range a {
		if v < m {
			m = v
		}
	}
	return m
}

func sum(a ints) int {
	if len(a) == 0 {
		return 0
	}
	sum := 0
	for _, e := range a {
		sum += e
	}
	return sum
}
func find(n int, a ints) int {
	for i, v := range a {
		if n == v {
			return i
		}
	}
	return -1
}

C++: /* Dynamic Programming C/C++ implementation of LCS problem */
#include <cstdio>
#include <iostream>
#include <string>
using namespace std;

int max(int a, int b);
/* Returns length of LCS for X[0..m-1], Y[0..n-1] */
int lcs( string X, string Y, int m, int n ) {
    int L[m + 1][n + 1];
    int i, j;
    /* Following steps build L[m+1][n+1] in bottom up fashion. Note
       that L[i][j] contains length of LCS of X[0..i-1] and Y[0..j-1]*/

 for (i=0; i<=m; i++) {
 for (j=0; j<=n; j++) {
 if (i == 0 || j == 0) L[i][j] = 0;
 else if (X[i-1] == Y[j-1]) {L[i][j] = L[i-1][j-1] + 1;}
 else
          L[i][j] = max(L[i-1][j], L[i][j-1]);
      }
 }

 //int index = L[m][n];

 /**if (index == 0) {printf("*"); return 0;}
 char lcs[index+1];
 lcs[index] = '\0'; // Set the terminating character

    // Start from the right-most-bottom-most corner and
    // one by one store characters in lcs[]
    i = m,
    j = n;
    while (i > 0 && j > 0 )
    {
        // If current character in X[] and Y are same, then
        // current character is part of LCS
        if (X[i-1] == Y[j-1])
        {
            lcs[index-1] = X[i-1]; // Put current character in result
            i--; j--; index--;     // reduce values of i, j and index
        }

            // If not same, then find the larger of two and
            // go in the direction of larger value
        else if (L[i-1][j] > L[i][j-1])
            i--;
        else
            j--;
    }

    printf("%s\n",lcs);**/

    /* L[m][n] contains length of LCS for X[0..n-1] and Y[0..m-1] */
    return L[m][n];
}

/* Utility function to get max of 2 integers */
int max(int a, int b) {
    return (a > b)? a : b; }

/* Driver program to test above function */
int main() {
    int N;
    scanf("%d",&N);
    for (int i = 0; i < N; i++) {
        int m ;
        int n ;
        string X;
        string Y;
        cin >> X >> Y;
        m = X.length();
        n = Y.length();
        cout << lcs(X, Y, m, n) << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;
int A[1005][1005]={};

int main() {
  int i,j,k,q;
  cin >> q;
  string a,b;
  for(i=0;i<q;i++) {
    cin  >> a >> b;
    int al = a.size();
    int bl = b.size();
    for(j=1;j<=al;j++) {
      for(k=1;k<=bl;k++) {
        if(a[j]==b[k]) {
          A[j][k]=A[j-1][k-1]+1;
        } else {
          A[j][k]=max(A[j][k-1],A[j-1][k]);
        }
      }
    }
    cout << A[al][bl] << endl;
  }
  return 0;
}

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

using namespace std;

int main () {

    int N, m, n, i, j, k, c[1001][1001];
    string x, y;

    cin >> N;

    for (k = 0; k < n; k++) {
        cin >> x >> y;
        m = x.size ();
        n = y.size ();

        for (i = 1; i < m + 1; i++) {
            for (j = 1; j <= n + 1; j++) {

                if (x[i - 1] == y[j - 1]) {
                    c[i][j] = c[i - 1][j - 1] + 1;
                } else {
                    c[i][j] = max (c[i - 1][j], c[i][j - 1]);
                }

            }
        }

    cout << c[p][q] << endl;

    }

}