Go: package main

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

const max int = 1000 + 1
var A [][]int

func lcs(x, y string) int {
	x = " " + x
	y = " " + y
	for i:=0;i<len(x); i++ {
		for j:=0;j<len(y); j++ {
			A[i][j] = 0
		}
	}
	for i:=1; i<len(x); i++ {
		for j:=1; j<len(y); j++ {
			if x[i] == y[j] {
				A[i][j] = A[i-1][j-1] + 1
			} else if A[i-1][j] > A[i][j-1] {
				A[i][j] = A[i-1][j]
			} else {
				A[i][j] = A[i][j-1]
			}
		}
	}
	return A[len(x)-1][len(y)-1]
}

func nextInt(scanner *bufio.Scanner) int {
	scanner.Scan()
	num, _ := strconv.Atoi(scanner.Text())
	return num 
}

func nextStr(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}


func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	A = make([][]int, max)
	for i := range A {
		A[i] = make([]int, max)
	}
	n := nextInt(scanner)
	for i:=0; i<n; i++ {
		x := nextStr(scanner)
		y := nextStr(scanner)
		fmt.Printf("%d\n", lcs(x, y))
	}
}

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))

Python: q = int(input())

for i in range(q):
    x = input()
    y = input()
 
    l = []
    for j, s in enumerate(x):
        l.append([])
        l[j].append(0)
        if j == 0:
            l[j].append(y.find(s))
        else:
            for k, t in enumerate(l[j - 1][:-1]):
                endPos = y.find(s, t + 1)
                if endPos != -1:
                    l[j].append(min(endPos, l[j - 1][k + 1]))
            endPos = y.find(s, l[j - 1][-1] + 1)
            if endPos != -1:
                l[j].append(endPos)

    print(len(l[len(x) - 1]) - 1)

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):
        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: def len_LCS(X,Y):
    lcs_row = [0 for _ in range(len(X)+1)]
    for yc in Y:
        lcs_row_p = lcs_row[:]
        # lcs_row_p: [i] [i+1]
        # lcs_row  : [i] [i+1]
        for (i,xc) in enumerate(X):
            if xc == yc:
                lcs_row[i+1] = lcs_row_p[i] + 1
            elif lcs_row[i] > lcs_row_p[i+1]:
                lcs_row[i+1] = lcs_row[i]
    return lcs_row[-1]
        
if __name__=='__main__':
    n = int(input())
    for _ in range(n):
        X = input()
        Y = input()
        print(len_LCS(X,Y))

Python: def Ics(X, Y):
    m = len(X)
    n = len(Y)
    maxl = 0
    for i in range(m + 1):
        c[i][0] = 0
    for j in range(1, n + 1):
        c[0][j] = 0
    for i in range(1, m + 1):
        for j in range(1, n + 1):
            if(X[i] == Y[j]):
                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]
            maxl = max(maxl, c[i][j])
    return maxl

q = int(input().rstrip())
t = []
for i in range(n):
    s1 = input().rstrip()
    s2 = input().rstrip()
    t.append(lcs(s1, s2))
print(*t, sep="\n")

Python: import sys

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)
    #pring(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 dp[i][j] is not None:
        #pring(" "*depth + "(%d, %d) : %d - hit" % (i, j, dp[i][j]))
        return dp[i][j]
    if i == 0 or j == 0:
        dp[i][j] = 0
        #pring(" "*depth + "(%d, %d) : %d - zero" % (i, j, dp[i][j]))
        return 0
    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
        #pring(" "*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))
    #pring(" "*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))