Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

type Position struct {
	X int
	Y int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}
	for i := 0; i < n; i++ {
		strX := nextText(sc)
		strY := nextText(sc)
		fmt.Println(calcLcs(strX, strY))
	}
}

func calcLcs(strX, strY string) int {
	return lcs(strX, strY, Position{0, 0}, make(map[Position]int))
}

func lcs(strX string, strY string, position Position, memo map[Position]int) int {
	if position.X >= len(strX) || position.Y >= len(strY) {
		return 0
	}
	if v, ok := memo[position]; ok {
		return v
	}
	if strX[position.X] == strY[position.Y] {
		result := lcs(strX, strY, Position{position.X + 1, position.Y + 1}, memo)
		memo[position] = result + 1
		return memo[position]
	} else {
		result1 := lcs(strX, strY, Position{position.X + 1, position.Y}, memo)
		result2 := lcs(strX, strY, Position{position.X, position.Y + 1}, memo)
		var result int
		if result1 > result2 {
			result = result1
		} else {
			result = result2
		}
		memo[position] = result
		return result
	}
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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)



def solve():

    N = int(input())

    for _ in range(N):

        x = input()

        y = input()

        print(lcs(x, y))



if __name__ == '__main__':

    solve()

Python: # 38

import sys


def lcs(X, Y):
    l_x = len(X)
    l_y = len(Y)
    # dp[i][j] : Xのi文字目、Yのj文字目までから構成される最長部分列数
    dp = [[0] * (l_y+1) for _ in range(l_x+1)]
    for i in range(l_x):
        for j in range(l_y):
            if X[i] == Y[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[-1][-1]


def lcs_s(X, Y):
    L = []
    for yk in Y:
        bgn_idx = 0
        for i, cur_idx in enumerate(L):
            chr_idx = X.find(yk, bgn_idx) + 1
            if not chr_idx:
                break
            L[i] = min(cur_idx, chr_idx)
            bgn_idx = cur_idx
        else:
            chr_idx = X.find(yk, bgn_idx) + 1
            if chr_idx:
                L.append(chr_idx)
    return len(L)


Q = int(input())
for _ in range(Q):
    X = sys.stdin.readline().rstrip()
    Y = sys.stdin.readline().rstrip()
    print(lcs_s(X, Y))

Python: import sys

def dp_init(m, n):
    return [[0] * n] * m

def solve(str_a, str_b):
    dp = dp_init(len(str_a), len(str_b))
    return rec(len(str_a), len(str_b), str_a, str_b, dp)

def rec(i, j, str_a, str_b, dp):
    if i-1 == 0 or j-1 == 0:
        return 0
    if dp[i-1][j-1] > 0:
        return dp[i-1][j-1]
    if str_a[i-1] == str_b[j-1]:
        dp[i-1][j-1] = rec(i-1, j-1, str_a, str_b, dp) + 1
        print("(%d, %d) : %d" % (i-1, j-1, dp[i-1][j-1]))
        return dp[i-1][j-1]
    dp[i-1][j-1] = max(rec(i, j-1, str_a, str_b, dp), rec(i-1, j, str_a, str_b, dp))
    print("(%d, %d) : %d" % (i-1, j-1, dp[i-1][j-1]))
    return dp[i-1][j-1]

nb_pairs = int(input())
pairs = []
for i in range(0, nb_pairs):
    pairs.append((input(), input()))

for i in range(0, nb_pairs):
    str_a, str_b = pairs[i]
    print(solve(str_a, str_b))

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)