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
}

Python: n = int(input())

def lcs(x, y):
    xlen = len(x)
    ylen = len(y)
    if xlen == 0 or ylen == 0:
        return 0
    elif x[xlen-1] == y[ylen-1]:
        return lcs(x[:-1], y[:-1]) + 1
    else:
        return max(lcs(x, y[:-1]), lcs(x[:-1], y))

for i in range(n):
    x = input()
    y = input()
    print(lcs(x, y))

Python: def lcs(X,Y):
    f=[[0 for i in range(len(Y))]for j in range(len(X))]
    for i in range(1,len(X)):
        for j in range(1,len(Y)):
            if X[i]==Y[j]:
                f[i][j]=f[i-1][j-1]+1
            else:
                f[i][j]=max(f[i-1][j],f[i][j-1])
    return f[len(X)-1][len(Y)-1]

q=int(input())
A=[0 for i in range(q)]
for i in range(q):
    X=input()
    Y=input()
    A[i]=lcs(X,Y)

for i in range(q):
    print(A[i])

Python: """
problem statment url: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_10_C
"""

from __future__ import division
from sys import stdin, maxint

def lcs(s1, s2):
	dp = [[0 for _ in xrange(len(s2) + 1)] for _ in xrange(2)]

	for i in xrange(1, len(s1) + 1):
		for j in xrange(1, len(s2) + 1):
			if s1[i - 1] == s2[j - 1]:
				dp[i & 1][j] = dp[1 - i & 1][j - 1] + 1
			else:
				dp[i & 1][j] = max(dp[1 - i & 1][j], dp[i & 1][j - 1])

	return dp[len(s1) & 1][len(s2)]

if __name__ == '__main__':
	tc = int(stdin.readline())
	for _ in range(tc):
		sa = stdin.readline().strip()
		sb = stdin.readline().strip()
		print(lcs(sa, sb))

Python: #JOI
def main():
    X=input()
    Y=input()
    dp=[[0 for y in range(1+len(Y))] for x in range(1+len(X))]
    for x in range(len(X)):
        for y in range(len(Y)):
            now=0
            dp[x][y]=max(dp[x-1][y],dp[x][y-1])
            for x1 in range(Y[:y+1].count(X[x])):
                idx=now+Y[now:y+1].index(X[x])
                now=idx+1
                dp[x][y]=max(dp[x-1][idx-1]+1,dp[x][y])
            now=0
            for y1 in range(X[:x+1].count(Y[y])):
                idx=now+X[now:x+1].index(Y[y])
                now=idx+1
                dp[x][y]=max(dp[idx-1][y-1]+1,dp[x][y])
    print(dp[len(X)-1][len(Y)-1])
for i in range(int(input())):
    main()