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: # -*- coding: utf-8 -*-

import random
import sys
import os
import pprint


def LCS(s0, s1):
    m = len(s0)
    n = len(s1)

    # memo[i][j]
    memo = [[0 for j in range(n)] for i in range(m)]

    # fill at index 0
    for i in range(m):
        if s1[0] in s0[0:i+1]:
            memo[i][0] = 1
    for j in range(n):
        if s0[0] in s1[0:j+1]:
            memo[0][j] = 1

    # fill memo
    for i in range(1, m):
        for j in range(1, n):
            # same last
            if s0[i] == s1[j]:
                memo[i][j] = memo[i-1][j-1] + 1
            else:
                memo[i][j] = max(memo[i-1][j], memo[i][j-1])
    return memo[m-1][n-1]

#fd = os.open('ALDS1_10_C.txt', os.O_RDONLY)
#os.dup2(fd, sys.stdin.fileno())

n = int(input())
for _ in range(n):
    s0 = input()
    s1 = input()
    l = LCS(s0, s1)
    print(l)

Python: from collections import defaultdict
q = int(input())
for _ in range(q):
    x = input()
    y = input()
    len_x = len(x)
    len_y = len(y)
    if len_x < len_y:
        len_x, len_y = len_y, len_x
        x, y = y, x
    set_x = set(x)
    c = defaultdict(list)
    for i, s in enumerate(x):
        c[s].append(i)
    li = [0] * len_x
    for s in y:
        for i in c[s][::-1]:
            if i == 0:
                li[i] = 1
            else:
                li[i] = max(li[:i]) + 1
    print(max(li))

Python: n = int(input())
for _ in range(n):
    a, b = input(), input()
    indices = []
    for cb in b:
        bgn_idx = 0
        for i in range(len(indices) + 1):
            chr_idx = a.find(cb, bgn_idx) + 1
            if chr_idx:
                if i < len(indices):
                    bgn_idx = indices[i]
                    if chr_idx < bgn_idx:
                        indices[i] = chr_idx
                else:
                    indices.append(chr_idx)
            else:
                break
    print(len(indices))

Python: def lcs(X, Y):
    m, n = len(X), len(Y)
    cost = [[1] * (n) for _ in range(m)]
    for i in range(0, m):
        if i == 0:
            continue
        for j in range(0, n):
            if j == 0:
                continue
            if X[i - 1] == Y[j - 1]:
                cost[i][j] = cost[i - 1][j - 1] + 1
            else:
                cost[i][j] = max(cost[i][j - 1], cost[i - 1][j])
    return cost[-1][-1]

n = int(input())
for _ in range(n):
    X, Y = input(), input()
    print(lcs(X, Y))

Python: # http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_10_C&lang=ja
# 最長共通部分文字列
import sys
read = sys.stdin.read
readline = sys.stdin.readline
readlines = sys.stdin.readlines

# dp[i][j] := Sのi番目までとTのj番目までのLCS
# アルゴリズム的には正しいがTLE
def LCS(S, T):
    n = len(S)
    m = len(T)

    dp = [[0] * (m+1) for _ in range(n+1)]

    for i in range(n):
        S_i = S[i]
        for j in range(m):
            if S_i == T[j]:
                dp[i+1][j+1] = dp[i][j] + 1
            else:
                dp[i+1][j+1] = max(dp[i+1][j], dp[i][j+1])
    
    return dp[n][m]


def LCS2(S, T):
    L = []
    for t in T:
        t_idx = 0  # 検索開始位置
        for i, cur_idx in enumerate(L):
            chr_idx = S.find(t, t_idx) + 1
            if not chr_idx:
                break
            L[i] = min(cur_idx, chr_idx)
            t_idx = cur_idx
        else:
            chr_idx = S.find(t, t_idx) + 1
            if chr_idx:
                L.append(chr_idx)
    
    return len(L)


def main():
    q = int(readline())
    xy = read().split()

    ans = []
    for X, Y in zip(*[iter(xy)]*2):
        ans.append(LCS2(X, Y))

    print("\n".join(map(str, ans)))


if __name__ == "__main__":
    main()

Python: q = int(input())

def lcs(X, Y):
    dp = [0]*(len(Y)+1)
    
    for x in X:
        tmp = dp[:]
        for j, y in enumerate(Y):
            if x == y:
                dp[j+1] = tmp[j] + 1
            elif dp[j+1] < dp[j]:
                dp[j+1] = dp[j]
                               
    return dp[-1]
    
for _ in range(q):
    X = input()
    Y = input()
    print(lcs(X, Y))

Python: import sys

sys.setrecursionlimit(1000000)


def lcd(x0, y0):
    lx, ly = len(x0), len(y0)
    memo = [[None] * ly for _ in range(lx)]

    def memoize(x, y):
        if x < 0 or y < 0:
            return 0
        if memo[x][y] is not None:
            return memo[x][y]
        result = memo[x][y] = main(x, y)
        return result

    def main(x, y):
        if x0[x] == y0[y]:
            return memoize(x - 1, y - 1) + 1
        return max(memoize(x - 1, y), memoize(x, y - 1))

    return main(lx - 1, ly - 1)


n = int(input())
while n:
    print(lcd(input(), input()))
    n -= 1