Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

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

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)
	for i := 0; i < n; i++ {
		x := getNextString(scanner)
		y := getNextString(scanner)

		fmt.Fprintln(writer, lcs(x, y))
	}

	writer.Flush()
}

func lcs(x, y string) int {
	lx := len(x)
	ly := len(y)
	dp := make([][]int, lx+1)
	for i := 0; i <= lx; i++ {
		dp[i] = make([]int, ly+1)
	}
	for i := 0; i < lx; i++ {
		for ii := 0; ii < ly; ii++ {
			if x[i] == y[ii] {
				dp[i+1][ii+1] = dp[i][ii] + 1
				continue
			}
			dp[i+1][ii+1] = dp[i][ii+1]
			if dp[i+1][ii] > dp[i+1][ii+1] {
				dp[i+1][ii+1] = dp[i+1][ii]
			}
		}
	}
	return dp[lx][ly]
}

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)

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

Python: import sys, os, math, bisect, itertools, collections, heapq, queue, copy, array

# from scipy.sparse.csgraph import csgraph_from_dense, floyd_warshall
# from decimal import Decimal
# from collections import defaultdict, deque

sys.setrecursionlimit(10000000)

ii = lambda: int(sys.stdin.buffer.readline().rstrip())
il = lambda: list(map(int, sys.stdin.buffer.readline().split()))
fl = lambda: list(map(float, sys.stdin.buffer.readline().split()))
iln = lambda n: [int(sys.stdin.buffer.readline().rstrip()) for _ in range(n)]

iss = lambda: sys.stdin.buffer.readline().decode().rstrip()
sl = lambda: list(map(str, sys.stdin.buffer.readline().decode().split()))
isn = lambda n: [sys.stdin.buffer.readline().decode().rstrip() for _ in range(n)]

lcm = lambda x, y: (x * y) // math.gcd(x, y)

MOD = 10 ** 9 + 7
MAX = float('inf')


def lcs(X, Y):
    dp = []
    for y in Y:
        bgn_idx = 0
        for i, cur_idx in enumerate(dp):
            # 既に探索済みの最長文字列を更新
            chr_idx = X.find(y, bgn_idx) + 1
            if not chr_idx:
                break
            dp[i] = min(chr_idx, cur_idx)
            bgn_idx = cur_idx
        else:
            chr_idx = X.find(y, bgn_idx) + 1
            if chr_idx:
                dp.append(chr_idx)
    return len(dp)


def main():
    if os.getenv("LOCAL"):
        sys.stdin = open("input.txt", "r")

    N = ii()
    for _ in range(N):
        X, Y = iss(), iss()
        print(lcs(X, Y))


if __name__ == '__main__':
    main()

Python: #coding:utf-8
from copy import deepcopy
import numpy as np
n = int(input())

def lcs(X,Y):
    m = len(X)
    n = len(Y)
    c = [[False for i in range(n+1)] for j in range(m+1)]
    for i in range(m+1):
        c[i][0] = 0
    for i in range(n+1):
        c[0][i] = 0
    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]
    c = np.array(c)
    return c[m][n]
                            
        
for  i in range(n):
    A = input()
    B = input()
    a = lcs(A,B)
    print(a)

Python: def longest_common(x, y):
    cost = [0]
    for c in y:
        for i in range(len(cost) -1, -1, -1):
            index = x.find(c, cost[i]) + 1
            if index:
                if i + 1 < len(cost):
                    cost[i + 1] = min(cost[i + 1], index)
                else:
                    cost.append(index)
    return len(cost)  - 1
            

n = int(input())
for _ in range(n):
    x = input()
    y = input()
    print(longest_common(x, y))

Python: a=''
for _ in[0]*int(input()):
 X,z=input(),[]
 for y in input():
  s=i=0
  for k in z:
   t=X.find(y,s)+1
   if t<1:break
   if t<k:z[i]=t
   s=k;i+=1
  else:
   t=X.find(y,s)+1
   if t:z+=[t]
 a+=f'\n{len(z)}'
print(a[1:])

Python: def lcs(X,Y):
    f=[[0 for i in range(len(Y)+1)]for j in range(len(X)+1)]
    for i in range(len(X)):
        for j in range(len(Y)):
            if X[i]==Y[j]:
                f[i+1][j+1]=f[i][j]+1
            else:
                f[i+1][j+1]=max(f[i][j+1],f[i+1][j])
    return f[len(X)][len(Y)]

q=int(input())
A=[0 for i in range(q)]
for i in range(q):
    X=input()
    Y=input()
    A[i]=lcs(X,Y)

for i in range(q):
    print(A[i])