Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	Q := sc.nextInt()
	for q := 0; q < Q; q++ {
		X, Y := sc.nextStr(), sc.nextStr()
		xLen, yLen := len(X), len(Y)
		dp := make([][]int, xLen+1)
		for i := 0; i <= xLen; i++ {
			dp[i] = make([]int, yLen+1)
		}
		for x := 0; x <= xLen; x++ {
			for y := 0; y <= yLen; y++ {
				if x == 0 || y == 0 {
					dp[x][y] = 0
				} else if X[x-1] == Y[y-1] {
					dp[x][y] = dp[x-1][y-1] + 1
				} else {
					dp[x][y] = max(dp[x-1][y], dp[x][y-1])
				}
			}
		}
		fmt.Fprintln(wtr, dp[xLen][yLen])
	}

	wtr.Flush()
}

Python: def prep_array(X, Y):
    c = [[0]*1001 for _ in range(1000+1)]
    return c


def calc_lcs(X, Y, c):
    m = len(X)
    n = len(Y)
    X = ' ' + X
    Y = ' ' + Y

    pre_row = c[0]
    for i in range(1, m+1):
        row = c[i]
        XX = X[i]
        for j in range(1, n+1):
            if XX == Y[j]:
                row[j] = pre_row[j - 1] + 1
            elif pre_row[j] >= row[j - 1]:
                row[j] = pre_row[j]
            else:
                row[j] = row[j - 1]
        pre_row = row
    return check_max(c)


def check_max(array):
    max_lcs = 0
    for row in array:
        temp_max = max(row)
        if temp_max > max_lcs:
            max_lcs = temp_max
    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, prep_array(X, Y))

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

Python: def longest_common_seq(x, y):
    m, n = len(x), len(y)
    
    dp = []
    for _ in range(m+1):
        dp.append([0]*(n+1))

    for i in range(m):
        for j in range(n):
            if x[i] == y[j]:
                dp[i][j] = dp[i-1][j-1] + 1
            else:
                dp[i][j] = max(dp[i-1][j], dp[i][j-1])

    return dp[m-1][n-1]



if __name__ == '__main__':
    q = int(input())  # 1 .. 150
    for _ in range(q):
        x = input()
        y = input()
        l = longest_common_seq(x,y)
        print(l)

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])