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 calc_lcs(X, Y):
    from array import array
    m = len(X)
    n = len(Y)
    X = ' ' + X
    Y = ' ' + Y
    c = array('I', [0] * (1001 * 1001))
    for i in range(1, m+1):
        for j in range(1, n+1):
            if X[i] == Y[j]:
                c[i*1001 + j] = c[(i-1)*1001 + j - 1] + 1
            elif c[(i-1)*1001 + j] >= c[i*1001 + j - 1]:
                c[i*1001 + j] = c[(i-1)*1001 + j]
            else:
                c[i*1001 + j] = c[i*1001 + j - 1]
    return max(c)


if __name__ == '__main__':
    # ??????????????\???
    # num = int(input())
    f = open('input.txt')
    num = int(f.readline())

    for _ in range(num):
        # X = input()
        # Y = input()
        X = f.readline().strip()
        Y = f.readline().strip()

        # ???????????????
        result = calc_lcs(X, Y)

        # ???????????¨???
        print(result)

Python: 
def f(x,y):
	list=[0]
	for z in y:
		for i in range(len(list)-1,-1,-1):
			tmp=x.find(z,list[i])+1
			if tmp:
				if i+1 < len(list):
					list[i+1]=min(list[i+1],tmp)
				else:
					list.append(tmp)
	return len(list)-1
 
n=int(input())
for i in range(q):
	x=input()
	y=input()
	print(f(x,y))

Python: import sys
def longest_common_subsequence(line1, line2):
    n_rows = len(line2) + 1
    array = [0] * n_rows

    ix_ = [x for x in range(n_rows)]
    ix = [x+1 for x in range(n_rows)]

    for l1_letter in line1:
        prev_array = array[:]
        for i_row_, i_row, l2_letter in zip(ix_, ix, line2):
            if l1_letter == l2_letter:
                array[i_row] = prev_array[i_row_] + 1
            else:
                up = prev_array[i_row]
                left = array[i_row_]
                array[i_row] = up if up > left else left
    return array[-1]

calc_time = False
if calc_time: import time; start = time.time()
def main():
    n = int(input())
    lines = sys.stdin.readlines()
    for i in range(0, 2*n, 2):
        ans = longest_common_subsequence(lines[i].rstrip(), lines[i+1].rstrip())
        print(ans)
    return

main()
if calc_time:print("elapsed:",time.time()-start)

Python: n = int(input())


def lcs(s1, s2):
    N, M = len(s1), len(s2)

    for _ in range(N+1):
        c.append([0]*(M+1))

    for i in range(1, N+1):
        for j in range(1, M+1):
            if s1[i-1] == s2[j-1]:
                c[i][j] = c[i-1][j-1] + 1
            else:
                c[i][j] = max(c[i-1][j], c[i][j-1])


for _ in range(n):
    c = []
    s1 = input()
    s2 = input()
    lcs(s1, s2)
    print(c[len(s1)][len(s2)])
    # print(c[len(s1)], c[len(s2)])

Python: N = int(input())

for _ in range(N):
    x = input()
    y = input()
    m, n = len(x), len(y)
    dp = [[0 for i in range(n+1)] for j in range(m+1)]
    
    for i in range(1, m+1):
        for j in range(1, n+1):
            if x[i-1] == y[j-1]:
                dp[i][j] = dp[i-1][j-1] + 1
            else:
                dp[i][j] = max(dp[i][j-1], dp[i-1][j])
                
    print(dp[m][n])

Python: q = int(input())

for i in range(q):
    x = list(input())
    y = list(input())
    lcs = [[0 for i in range(len(x)+1)] for j in range(len(y)+1)]
    for i in range(1,len(y) + 1):
        for j in range(1,len(x) + 1):
            if x[j-1] != y[i-1]:
                lcs[i][j] = max(lcs[i-1][j-1],lcs[i][j-1],lcs[i-1][j])
            else:
                lcs[i][j] = max(lcs[i-1][j-1] + 1,lcs[i][j-1],lcs[i-1][j])
    print(lcs[i][j])

Python: import bisect
import collections
import heapq
import itertools
import operator
import sys

def lcs(x, y):
    dp = [[0] * 1010 for _ in range(1010)]
    for i, c in enumerate(y):
        if c == x[0]:
            dp[0][i] = 1
    for i, c in enumerate(x):
        if c == y[0]:
            dp[i][0] = 1
    for i in range(len(x)):
        for j in range(len(y)):
            if x[i] == y[j]:
                dp[i][j] = dp[i-1][j-1] + 1
            else:
                dp[i][j] = max(dp[i][j-1], dp[i-1][j])
    return dp[len(x)-1][len(y)-1]

def main():
    n = int(sys.stdin.readline())
    for _ in range(n):
        x = sys.stdin.readline().strip()
        y = sys.stdin.readline().strip()
        print(lcs(x, y))


if __name__ == '__main__':
    main()

Python: def num_substr(s, t):
    dp = {}
    for i in range(len(s) + 1):
        dp[i] = {0: 0}
    for j in range(len(t) + 1):
        dp[0][j] = 0
     
    for i in range(1,len(s)+1):
        si_1 = s[i-1]
        dpi = dp[i]
        dpi_1 = dp[i-1]
        for j in range(1,len(t)+1):
            d=1 if si_1 == t[j-1] and dpi_1[j-1] == dpi[j-1] else 0
            dpi[j] = max(dpi_1[j] ,
                           dpi[j-1] +d)
    return dp[len(s)][len(t)]
 
n = int(input())
for i in range(n):
    s = input()
    t = input()
    print(num_substr(s,t))

Python: q = int(input())

for i in range(q):
    X = input()
    Y = input()
    x = len(X)
    y = len(Y)
    X = ' ' + X
    Y = ' ' + Y
    dp = [[None] * (y + 1)] * (x + 1)
    for i in range(1, x+1):
        dp[i][0] = 0
    for i in range(1, y+1):
        dp[0][i] = 0
    for j in range(1, x + 1):
        for k in range(1, y + 1):
            if X[j - 1] == Y[k - 1]:
                dp[j][k] = dp[j - 1][k - 1] + 1
            else:
                dp[j][k] = max(dp[j - 1][k],dp[j][k - 1])
    print(dp[x][y])