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: import numpy as np
q = int(input())

for _ in range(q):
    X = np.array([ord(i) for i in input()])
    Y = np.array([ord(i) for i in input()])
    NX = len(X)
    NY = len(Y)
    dp = np.zeros((NX+1,NY+1), dtype=np.int64)
    for x in range(NX):
        yes = Y == X[x]
        no = Y != X[x]
        dp[x+1][1:][yes] = dp[x][:-1][yes] + 1
        dp[x+1][1:][no] = np.maximum(dp[x][1:][no], dp[x][:-1][no])
    print(dp[NX][NY])

Python: def ask(X,Y):

 a=len(X)
 b=len(Y)
 Z=[]
 for n in range(a):
  z=0
  c=0
  for i in range(n,a):
   for j in range(c,b):
    if(c==b-1):
     break
    if(X[i]==Y[j]):
     c=j
     break
     
  Z.append(z)

 Z.sort();
 return Z[a-1]


q=int(input())
Z=[]
for p in range(q):
 x=input()
 X=list(x)
 y=input()
 Y=list(y)
 z=ask(X,Y)
 Z.append(z)

for p in range(q):
 print(Z[p])

Python: #coding:UTF-8
def LCS(X,Y):
    count=0
    xlist=list(X)
    ylist=list(Y)
    anslist=[]
    ynum=0
    xnum=0
    yflag=False
    for i in range(len(ylist)):
        for j in range(i,len(xlist)):
            anslist.append([j,i])
    for i in range(len(anslist)):
        if xlist[anslist[i][0]]==ylist[anslist[i][1]] and ynum==anslist[i][1] and anslist[i][0]>=xnum:
            count+=1
            yflag=True
            ynum+=1
            xnum=anslist[i][0]
        if anslist[i][0]==len(xlist)-1:
            if yflag==True:
                yflag=False
            else:
                ynum+=1
    print(count)
if __name__=="__main__": 
    n=int(input())
    for i in range(n):
        X=input()
        Y=input()
        LCS(X,Y)

Python: def lcs(x,y,l,j,k):
	if(j==0 or k==0):
		return
	if(x[j-1]==y[k-1]):
		lcs(x,y,l,j-1,k-1)
		global c
		c+=1
	else:
		if l[j-1][k]>=l[j][k-1]:
			lcs(x,y,l,j-1,k)
		else:
			lcs(x,y,l,j,k-1)

q=int(input())
c=0
for i in range(q):
	x=list(input())
	y=list(input())
	l=[[0 for i in range(len(y)+1)] for j in range(len(x)+1)]

for j in range(1, len(x) + 1):
    for k in range(1, len(y) + 1):
        if x[j - 1] == y[k - 1]:
            a = 1
        else:
            a = 0
        l[j][k] = max(l[j-1][k-1] + a, l[j-1][k], l[j][k-1])
lcs(x,y,l,len(x),len(y))
print(c)

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
input:
3
abcbdab
bdcaba
abc
abc
abc
bc

output:
4
3
2

"""
import sys

sys.setrecursionlimit(int(1e5))


def lcs(A, B):
    m, n = len(A), len(B)
    dp = tuple([[0] * (n + 1) for _ in range(m + 1)])
    max_l = 0
    for i in range(1, m + 1):
        for j in range(1, n + 1):
            if A[i - 1] == B[j - 1]:
                dp[i][j] = dp[i - 1][j - 1] + 1
            else:
                dp[i][j] = max(dp[i - 1][j], dp[i][j - 1])
            max_l = max(max_l, dp[i][j])

    return max_l


def lcs_recursive(A, B, m, n):
    if m == 0 or n == 0:
        return 0
    elif A[m - 1] == B[n - 1]:
        return 1 + lcs_recursive(A, B, m - 1, n - 1)
    else:
        return max(lcs_recursive(A, B, m, n - 1), lcs_recursive(A, B, m - 1, n))


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    pair_num = int(_input[0])

    word_list = _input[1:]
    # assert len(word_list) == 2 * pair_num
    # for k in range(0, len(word_list), 2):
    #     print(lcs(word_list[k].strip(), word_list[k + 1].strip()))

    for pair in zip(word_list[::2], word_list[1::2]):
        w1, w2 = map(lambda x: x.strip(), pair)
        # l1, l2 = len(w1), len(w2)
        print(lcs(w1, w2))

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

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


def lcs(X, Y):
    memo = dict()
    for i in range(len(X)+1):
        memo[(i, 0)] = 0
    for j in range(len(Y)+1):
        memo[(0, j)] = 0
    for i, x in enumerate(X):
        for j, y in enumerate(Y):
            if x == y:
                memo[(i+1,j+1)] = memo[i, j] + 1
            else:
                memo[(i+1,j+1)] = max(memo[i, j+1], memo[i+1, j])
    return memo[(len(X), len(Y))]


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

Python: ans=[]
n=int(input("n="))
for i in range(n):
    X=input("X=")
    Y=input("Y=")
    com=[0]
    for i in X:
        for j in range(len(com)-1,-1,-1):
            tmp=X.find(i,com[j])+1
            if tmp:
                if j+1<len(com):
                    com[j+1]=min(com[j+1],tmp)
                else:
                    com.append(tmp)     
    ans.append(len(com)-1)
for i in range(n):
    print(ans[i])

Python: # -*- coding: utf-8 -*-
"""
http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_10_C

????????±?????¨??????
"""
# 3/5??§Time Limit Exceeded 14.27s ????????????5s??\???????????????????????????

def calc_lcs(X, Y):
    from array import array
    max_lcs = 0
    m = len(X)
    n = len(Y)
    X = ' ' + X
    Y = ' ' + Y
    c = array('l', [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())
    # f = open('input.txt')
    # num = int(f.readline())

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

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

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