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 -*-
"""
http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_10_C

最長共通部分列
"""


c = []
def prep_array(X, Y):
    global c
    """ 値が0の2次元配列を用意する。サイズは入力データの最大値を想定して縦横(1000+1)以上必要。 """
    # from array import array
    # c = [array('I', [0] * (len(X)+1)) for _ in range(len(Y)+1)]  #  arrayで用意
    c = [[0]*(len(Y)+2) for _ in range(len(X)+2)] #  リストで用意
    return c


def check_max(array):
    """ 2次元配列の中の最大の値を返す """
    max_lcs = 0
    for row in array:
        temp_max = max(row)
        if temp_max > max_lcs:
            max_lcs = temp_max
    return max_lcs


def calc_lcs4(X, Y, c):
    """
    Y[j]のアクセス方法を変更
    リストの値を一旦変数に保存するように変更
    最長共通部分長を関数内で計算するように変更
    4/5 のテストデータを使用してプロファイリングすると実効時間は 5.6秒
    """
    X = ' ' + X
    Y = ' ' + Y
    m = len(X)
    n = len(Y)
    max_lcs = 0

    pre_row = c[0]
    for i in range(1, m):
        row = c[i]
        XX = X[i]
        for j, YY in enumerate(Y):
            if XX == YY:
                pr_j1 = pre_row[j - 1]
                row[j] = pr_j1 + 1
                if pr_j1+1 > max_lcs:
                   max_lcs = pr_j1 + 1
            else:
                pr_j = pre_row[j]
                r_j1 = row[j-1]
                if pr_j >= r_j1:
                    row[j] = pr_j
                else:
                    row[j] = r_j1
        pre_row = row
    return max_lcs


if __name__ == '__main__':
    # データの入力
    num = int(input())
    #f = open('input.txt')
    #num = int(f.readline())

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

        # 処理の実行
        result = calc_lcs4(X, Y, prep_array(X, Y))

        # 結果の表示
        print(result)

Python: def gen_dp(row, col):
  return [[0]*col for i in range(row)]

def solver(str_1 ,str_2):
  dp = gen_dp(len(str_2) + 1, len(str_1) + 1)
  for r in range(len(str_2)):
    for c in range(len(str_1)):
      if str_2[r] == str_1[c]:
        dp[r + 1][c + 1] = dp[r][c] + 1
      else:
        dp[r + 1][c + 1] = max(dp[r + 1][c], dp[r][c + 1])
  return dp[len(str_2)][len(str_1)]

n = int(input())
for _ in range(n):
  str_1 = input()
  str_2 = input()
  print(solver(str_1, str_2))

Python: from sys import stdin

X = [ 0 for i in range(1000) ]
Y = [ 0 for i in range(1000) ]


def getLCS() :
	xlen = len(X[l])
	ylen = len(Y[l])
	Z = [[0 for i in range(xlen+2)]for i in range(ylen+2)]


	for i in range(1,xlen+1) :
		for j in range(1,ylen+1) :
			if X[i-1] == Y[j-1] : Z[i][j] = Z[i-1][j-1] + 1
			elif Z[i-1][j] >= Z[i][j-1] : Z[i][j] = Z[i-1][j]
			else : Z[i][j] = Z[i][j-1]

	return Z[xlen][ylen]

n = int(input())
for l in range(n) :
	X[l] = stdin.readline().strip()
	Y[l] = stdin.readline().strip()
	print(getLCS())

Python: import sys


def lcs(X, Y):
    m = len(X)
    n = len(Y)
    c = [[0] * (n+1) if i == 0 else [0] + [None] * n for i 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]:
                c[i][j] = c[i-1][j-1] + 1
            elif c[i-1][j] >= c[i][j-1]:
                c[i][j] = c[i-1][j]
            else:
                c[i][j] = c[i][j-1]
    return c[m][n]


if __name__ == "__main__":
    n = int(sys.stdin.readline())
    inp = sys.stdin.readlines()
    for i in range(n):
        print(lcs(inp[2*i][:-1], inp[2*i+1][:-1]))

Python: def main(X, Y):
    M = len(Y)
    dp = [0]*(M+1)
    for i, x in enumerate(X):
        dp_pre = dp[:]
        for j, y in enumerate(Y):
            if x == y:
                dp[j+1] = dp_pre[j] + 1
            elif dp[j+1] < dp[j]:
                dp[j+1] = dp[j]
    return print(dp[M])


for _ in range(int(input())):
    X = input()
    Y = input()
    main(X, Y)

Python: def lcs(X,Y,p,q,Z):
    for i in range(p):
        for j in range(q):
            if X[i]==Y[j]:
                Z[i+1][j+1]=Z[i][j]+1
            else:
                if Z[i][j+1]>Z[i+1][j]:
                    Z[i+1][j+1]=Z[i][j+1]
                else:
                    Z[i+1][j+1]=Z[i+1][j]
    print(Z[p][q])

n=int(input())
for i in range(n):
    X=input()
    Y=input()
    p=len(X)
    q=len(Y)
    Z=[[0 for i in range(q+1)]for j in range(p+1)]
    lcs(X,Y,p,q,Z)

Python: 
def main():
    n = int(input())
    for i in range(n):
        a = input()
        b = input()
        na=len(a)
        nb=len(b)
        array = [[0]*nb]*na
        #array = [[0 for i in range(nb)] for j in range(na)]
        print(array)
        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] = array[i-1][j-1]+c 
                    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()