Go: package main

import (
	"fmt"
)

func main() {
	var q int
	fmt.Scan(&q)

	for i := 0; i < q; i++ {
		var x, y string
		fmt.Scan(&x)
		fmt.Scan(&y)

		xs := []rune(x)
		ys := []rune(y)

		xn := len(xs)
		yn := len(ys)
		dp := make([][]int, xn+1)
		for j := 0; j <= xn; j++ {
			dp[j] = make([]int, yn+1)
		}

		for j := 1; j <= xn; j++ {
			for k := 1; k <= yn; k++ {
				dp[j][k] = max(dp[j-1][k], dp[j][k-1])
				if xs[j-1] == ys[k-1] {
					dp[j][k] = max(dp[j][k], dp[j-1][k-1] + 1)
				} else {
					dp[j][k] = max(dp[j][k], dp[j-1][k-1])
				}
			}
		}
		fmt.Println(dp[xn][yn])
	}
}

func max(a, b int) int {
	if a < b {
		return b
	} else {
		return a
	}
}

Python: def lcs(l1,l2):
    dp=[[0 for x in range(len(l2)+1)] for y in range(len(l1)+1)]

    for i in range(1,len(l1)+1):
        for j in range(1,len(l2)+1):
            if l1[i-1]==l2[j-1]:
                dp[i][j]=dp[i-1][j-1]+1
            else:
                dp[i][j]=max(dp[i-1][j],dp[i][j-1])
                
    return dp[len(l1)][len(l2)]


a=[]
n=int(input())
for i in range(n):
    l1=list(input())
    l2=list(input())
    a+=[lcs(l1,l2)]

for i in range(n):
    print(a[i])

Python: def calc_lcs(X, Y):
    from array import array
    max_lcs = 0
    m = len(X)
    n = len(Y)
    X = ' ' + X
    Y = ' ' + Y
    c = array('b', [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]
            max_lcs = max(max_lcs, c[i*1001 + j])
    return max_lcs


if __name__ == '__main__':
    # ??????????????\???
    num = int(input())
    # num = 1

    for _ in range(num):
        X = input()
        Y = input()
        # X = 'abcbdab'
        # Y = 'bdcaba'


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

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

Python: n = int(input())
for _ in range(n):
    a, b = input(), input()
    i, j = len(a), len(b)
    prev = [0] * (j + 1)
    for ca in a:
        cur = [0] * (j + 1)
        for l, cb in enumerate(b):
            if ca == cb:
                cur[l + 1] = prev[l] + 1
            else:
                cur[l + 1] = max(cur[l], prev[l + 1])
        prev = cur
    print(prev[-1])

Python: import sys
sys.setrecursionlimit(10000)
def lcs(X, Y):
    i = len(X)
    j = len(Y)
    if not i or not j:
        return 0
    if memo[i][j] >= 0:
        return memo[i][j]
    if X[-1] == Y[-1]:
        memo[i][j] = 1 + lcs(X[:-1], Y[:-1])
        return memo[i][j]
    else:
        memo[i][j] = max(lcs(X[:-1], Y), lcs(X, Y[:-1]))
        return memo[i][j]

q = int(input())
for i in range(q):
    X = input()
    Y = input()
    memo = [[-1 for j in range(len(Y) + 1)] for i in range(len(X) + 1)]
    print(lcs(X, Y))

Python: def lcs(a_str, b_str):
    dp = [[0 for n in range(len(a))] for m in range(len(b_str))]
    for i in range(len(b_str)):
        for j in range(len(a_str)):
            if i == 0 or j == 0:
                dp[i][j] = int(a_str[j] == b_str[i])
            else:
                dp[i][j] = max(dp[i - 1][j - 1] + int(a_str[j] == b_str[i]), dp[i - 1][j], dp[i][j - 1])
    return dp[len(b_str) - 1][len(a_str) - 1]

trial = int(input())

for _ in range(trial):
    a = input()
    b = input()
    a = {k:v for k, v in enumerate(a)}
    b = {k:v for k, v in enumerate(b)}
    print(lcs(a, b))

Python: import sys

LEN_MAX = 1000
sys.setrecursionlimit(LEN_MAX + 3)

def dp_init(m, n):
    ret = []
    for i in range(m):
        ret.append([None] * n)
    return ret

def solve(str_a, str_b):
    dp = dp_init(len(str_a)+1, len(str_b)+1)
    #print(dp)
    return rec(len(str_a), len(str_b), str_a, str_b, dp, 0)

def rec(i, j, str_a, str_b, dp, depth):
    if i == 0 or j == 0:
        #print(" "*depth + "(%d, %d) : %d - zero" % (i, j, dp[i][j]))
        return 0
    if dp[i][j] is not None:
        #print(" "*depth + "(%d, %d) : %d - hit" % (i, j, dp[i][j]))
        return dp[i][j]
    if str_a[i-1] == str_b[j-1]:
        dp[i][j] = rec(i-1, j-1, str_a, str_b, dp, depth+1) + 1
        #print(" "*depth + "(%d, %d) : %d" % (i, j, dp[i][j]))
        return dp[i][j]

    dp[i][j] = max(rec(i, j-1, str_a, str_b, dp, depth+1), rec(i-1, j, str_a, str_b, dp, depth+1))
    #print(" "*depth + "(%d, %d) : %d" % (i, j, dp[i][j]))
    return dp[i][j]

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: import sys
sys.setrecursionlimit(200000)
from collections import defaultdict
from bisect import bisect_left, bisect, insort_left, insort
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
    c = defaultdict(list)
    for i, s in enumerate(x):
        c[s].append(i)
    ans = 0
    @lru_cache(maxsize=1000)
    def f(x_i, y_i, cnt):
        if x_i >= len_x or y_i >= len_y:
            global ans
            if ans < cnt:
                ans = cnt
            return
        f(x_i, y_i + 1, cnt)
        s = bisect_left(c[y[y_i]], x_i)
        if s < len(c[y[y_i]]) and c[y[y_i]][s] < len_x:
            f(c[y[y_i]][s] + 1, y_i + 1, cnt + 1)
    f(0, 0, 0)
    print(ans)

Python: 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):
        return memoize(x - 1, y - 1) + 1 if x0[x] == y0[y] else 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

Python: q = int(input())
ans = []
for _ in range(q):
    X = input()
    Y = input()
    NX = len(X)
    NY = len(Y)
    dp = [[0] * (NY+1) for _ in range(NX+1)]
    jx = [0 for _ in range(NX)]
    jy = [0 for _ in range(NY)]
    for x in range(NX):
        for y in range(NY):
            if jx[x] == 0 and jy[y] == 0 and X[x] == Y[y]:
                dp[x+1][y+1] = max(dp[x][y+1], dp[x+1][y]) + 1
                jx[x] = 1
                jy[y] = 1
            else:
                dp[x+1][y+1] = max(dp[x][y+1], dp[x+1][y])

    ans.append(dp[NX][NY])
for a in ans:
    print(a)

Python: # 最長共通部分列(LCS:Longest Common Subsequence)

q = int(input())

def LCS(X,Y):
    XL = len(X)
    YL = len(Y)
    dp = [0]*(YL+1)
    for i in range(XL):
        dpnew = dp[:]
        for j in range(YL):
            if X[i] == Y[j]:
                dp[j+1] = dpnew[j] + 1
            elif dp[j+1] < dp[j]:
                dp[j+1] = dp[j]
    print(dp[YL])


for i in range(q):
    X = list(input())
    Y = list(input())
    LCS(X,Y)

Python: # -*- coding: utf-8 -*-
def lcs(x, y):
    dp = {(0, 0): 0}
    for i in range(1, len(x) + 1):
        dp[(i, 0)] = 0
    for j in range(1, len(y) + 1):
        dp[(0, j)] = 0
    for i in range(1, len(x) + 1):
        for j in range(1, len(y) + 1):
            if x[i - 1] == y[j - 1]:
                dp[(i, j)] = dp[(i - 1, j - 1)] + 1
            else:
                dp[(i, j)] = max(dp[(i - 1, j)], dp[(i, j - 1)])

    return dp[(len(x), len(y))]


if __name__ == '__main__':
    q = int(input())
    for i in range(q):
        x = input()
        y = input()
        print(lcs(x, y))