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: def lcs_hs(s1, s2):
    from bisect import bisect_left

    s2, lis, result = s2[::-1], [], 0
    find, append = s2.find, lis.append

    for c in s1:
        i = find(c)+1
        while i:
            j = bisect_left(lis, -i)
            if j >= result:
                append(-i)
                result += 1
            else:
                lis[j] = -i
            i = find(c, i)+1

    return result


print(*(lcs_hs(input(), input()) for _ in [0]*int(input())), sep="\n")

Python: import sys
import functools as ft
sys.setrecursionlimit(10000)

q = int(input())
X = ""
Y = ""
memo = [[]]

def print_memo() :
    for x in range(len(X)+1):
        print(ft.reduce(lambda x,y: x + str(y) + "\t" ,memo[x], ""))

def LCS(x, y):
    if (x < 0) or (y < 0):
        return 0
    elif memo[x][y] != -1:
        return memo[x][y]
    elif X[x] == Y[y]:
        memo[x][y] =  LCS(x-1, y-1) + 1
        return memo[x][y]
    else:
        memo[x][y] = max(LCS(x-1,y), LCS(x,y-1))
        return memo[x][y]


for c in range(q):
    X = input()
    Y = input()
    len_x = len(X)
    len_y = len(Y)
    memo = [[0 for j in range(len_y+1)] for i in range(len_x+1)]

    for x in range(1, len_x+1):
        for y in range(1, len_y+1):
            memo[x][y] = max(memo[x-1][y-1] + int(X[x-1]==Y[y-1]), memo[x-1][y], memo[x][y-1])

    print(memo[len_x][len_y])
    #print_memo()

Python: def main():
    n = int(input())
    result = []
    for i in range(n):
        a = input()
        b = input()
        array = [[1 for i in range(len(b))] for j in range(len(a))]
        for i in range(1, len(a)):
            for j in range(1, len(b)):
                c = 0
                if a[i] == b[j]:
                    c = 1
                array[i][j] = max(
                                    array[i-1][j],
                                    array[i][j-1],
                                    array[i-1][j-1]+c)
        result.append(array[len(a)-1][len(b)-1])
    for i in result:
        print(i)
if __name__ == "__main__":
    main()

Python: def f(i,j):
    if i == 0 or j == 0:
        if s1[i] == s2[j]:
            x[i][j] = 1
        else:
            if i == 0:
                x[i][j] = x[i][j-1]
            else:
                x[i][j] = x[i-1][j]
    elif s1[i] == s2[j]:
        x[i][j] = max(x[i-1][j-1]+1,x[i][j-1],x[i-1][j])
    else:
        x[i][j] = max(x[i-1][j-1],x[i][j-1],x[i-1][j])

n = int(input())
for i in range(n):
    s1 = input()
    s2 = input()
    x = [[0 for j in range(len(s2))]for k in range(len(s1))]
    for j in range(len(s1)):
        for k in range(len(s2)):
            f(j,k)
            
    print(x[len(s1)-1][len(s2)-1])

Python: 
def main():
    n = int(input())
    for i in range(n):
        a = input()
        b = input()
        na=len(a)
        nb=len(b)
        array = [[0 for i in range(nb)] for j in range(na)]
        for i in range(na):
            for j in range(nb):
                if i==0:
                    if a[i]==b[j]:
                        array[i][j]=1
                elif j==0:
                    if a[i]==b[j]:
                        array[i][j]=1
                else:
                    c = 0
                    if a[i] == b[j]:
                        c = 1
                    array[i][j] = max(
                                        array[i-1][j],
                                        array[i][j-1],
                                        array[i-1][j-1]+c)
        print(array[na-1][nb-1])
if __name__ == "__main__":
    main()

Python: def lcs(s1, s2):
    dp = []
    for s2_k in s2:
        bgn_idx = 0
        for i, cur_idx in enumerate(dp):
            chr_idx = s1.find(s2_k, bgn_idx) + 1
            if not chr_idx:
                break
            dp[i] = min(cur_idx, chr_idx)
            bgn_idx = cur_idx
        else:
            chr_idx = s1.find(s2_k, bgn_idx) + 1
            if chr_idx:
                dp.append(chr_idx)
    return len(dp)

n = int(input())
ans = []
for _ in range(n):
    x = input()
    y = input()
    ans.append(lcs(x, y))

for i in ans:
    print(i)

Python: def len_LCS(X,Y):
    Z = X
    if len(X) > len(Y): Z,Y = Y,X
    D = {}
    def len_LCS_core(Z,Y):
        if Z in D: return D[Z]
        if Z in Y:
            D[Z] = len(Z)
            return D[Z]
        D[Z] = 0
        if len(Z) < 2: return 0
        for i in range(len(Z)):
            D[Z] = max(D[Z], len_LCS_core(Z[:i]+Z[i+1:],Y))
        return D[Z]
    return len_LCS_core(Z,Y)
        
if __name__=='__main__':
    n = int(input())
    for _ in range(n):
        X = input()
        Y = input()
        print(len_LCS(X,Y))