Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	resolve()
}

func resolve() {
	n := scanInt(sc)
	results := []int{}
	for i := 0; i < n; i++ {
		results = append(results, resolveInstance())
	}
	for _, v := range results {
		fmt.Println(v)
	}
	return
}

func resolveInstance() int {
	x, y := scanString(sc), scanString(sc)
	lx, ly := len(x), len(y)
	dp := make([][]int, lx+1)
	dp[0] = make([]int, ly+1)
	for i := 1; i <= lx; i++ {
		dp[i] = make([]int, ly+1)
		dp[i][0] = dp[i-1][0]
		for j := 1; j <= ly; j++ {
			dp[i][j] = dp[i-1][j]
			if dp[i][j] < dp[i][j-1] {
				dp[i][j] = dp[i][j-1]
			}
			if x[i-1] == y[j-1] {
				cL := dp[i-1][j-1] + 1
				if dp[i][j] < cL {
					dp[i][j] = cL
				}
			}
		}
	}
	return dp[lx][ly]
}

const (
	remove = 0 + iota
	match
)

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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]
    return c[m][n]
                            
        
for  i in range(n):
    A = input()
    B = input()
    a = lcs(A,B)
    print(a)

Python: def calc_lcs(X, Y):
    m = len(X)
    n = len(Y)
    X = ' ' + X
    Y = ' ' + Y
    c = [[0]*1001 for i in range(1000+1)]
    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]
            else:
                c[i][j] = c[i][j - 1]
    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)

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

Python: q = int(input())
ans = []
for i in range(q):
    x = input()
    y = input()
    n = len(x)
    m = len(y)
    dp1 = [0]*(m+1)
    for i in range(n):
        s = x[i]
        dp2 = dp1[:]
        for j in range(m):
            if s == y[j]:
                dp1[j+1] = dp2[j]+1
            elif dp1[j+1] < dp1[j]:
                dp1[j+1] = dp1[j]
    ans+=[dp1[-1]]
print(*ans, sep="\n")

Python: def num_substr(s, t):
    sl = len(s)
    tl = len(t)
    dp = {}
    for i in range(sl + 1):
        dp[i] = {0: 0}
    for j in range(sl + 1):
        dp[0][j] = 0
     
    for i in range(1,sl+1):
        si_1 = s[i-1]
        dpi = dp[i]
        dpi_1 = dp[i-1]
        for j in range(1,tl+1):
            d=1 if si_1 == t[j-1] and dpi_1[j-1] == dpi[j-1] else 0
            dp[i][j] = max(dpi_1[j] ,
                           dpi[j-1] +d)
    return dp[len(s)][len(t)]
 
n = int(input())
for i in range(n):
    s = input()
    t = input()
    print(num_substr(s,t))

Python: def calc_lcs(X, Y):
    max_lcs = 0
    m = len(X)
    n = len(Y)
    X = ' ' + X
    Y = ' ' + Y
    c = [[0]*1001 for i in range(1000+1)]
    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]
            else:
                c[i][j] = c[i][j - 1]
            max_lcs = max(max_lcs, c[i][j])
    return max_lcs


if __name__ == '__main__':
    # ??????????????\???
    num = int(input())
    # X = 'abcbdab'
    # Y = 'bdcaba'

    for _ in range(num):
        X = input()
        Y = input()

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

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

Python: def lcs(s, t):
  slen = len(s)
  tlen = len(t)
  dp = [0] * (slen + 1)
  dp[0] = [0] * (tlen + 1)

  for i in range(1, slen + 1):
    dp_prev = dp[i-1]
    dp_cur  = [0] * (tlen + 1)
    c = s[i-1]
    for j in range(1, tlen + 1):
      if c == t[j-1]:
        dp_cur[j] = dp_prev[j-1] + 1
      else:
        dp_cur[j] = max(dp_cur[j-1], dp_prev[j])
    dp[i] = dp_cur

  return dp[slen][tlen]

n = int(raw_input())

for i in range(n):
  x = raw_input()
  y = raw_input()
  print(lcs(x, y))

Python: def lcs(X,Y):
    Xlength = len(X)
    Ylength = len(Y)

    for i in range(Xlength+1):
        c[i][0] = 0
    for i in range(Ylength+1):
        c[0][i] = 0

    for i in range(Xlength):
        for j in range(Ylength):
            if X[i] == Y[j]:
                c[i+1][j+1] = c[i][j]+1
            else:
                c[i+1][j+1] = max(c[i][j+1],c[i+1][j])

    return c[Xlength][Ylength]

    # print(X,Y)
    # if Xlength == 0 or Ylength == 0:
    #     c[Xlength][Ylength] = 0
    #     return c[Xlength][Ylength]
    #
    #
    #
    # if X[Xlength -1] == Y[Ylength -1]:
    #     if c[Xlength-1][Ylength-1] is not None:
    #         c[Xlength][Ylength] = c[Xlength-1][Ylength-1]+1
    #     else:
    #         c[Xlength][Ylength] = lcs(X[:Xlength-1], Y[:Ylength-1])+1
    # else:
    #     if c[Xlength-1][Ylength] is not None and c[Xlength][Ylength-1] is not None:
    #         c[Xlength][Ylength] = max(c[Xlength][Ylength-1],c[Xlength-1][Ylength])
    #     elif c[Xlength-1][Ylength] is not None:
    #         c[Xlength][Ylength] = max(lcs(X,Y[:Ylength-1]),c[Xlength-1][Ylength])
    #     elif c[Xlength][Ylength-1] is not None:
    #         c[Xlength][Ylength] = max(c[Xlength][Ylength-1],lcs(X[:Xlength-1],Y))
    #     else:
    #         c[Xlength][Ylength] = max(lcs(X,Y[:Ylength-1]),lcs(X[:Xlength-1],Y))
    #
    # return c[Xlength][Ylength]


n = int(input())
X = []
Y = []
c = [[None]*1001 for i in range(1001)]


for i in range(n):
    X.append(input())
    Y.append(input())

for i in range(n):
    # print(i)
    print(lcs(X[i],Y[i]))
    # c = [[None]*1001 for i in range(1001)]

Python: def main():
    num = int(input())
    A = []
    for i in range(num):
        X = input()
        Y = " " + input()
        lx = len(X)
        ly = len(Y)
        T = [0] * ly
        for j in range(lx):
            xj = X[j]
            C = T[:]
            for k in range(1,ly):
                k1 = k-1
                if xj == Y[k]:
                    T[k] = C[k1] + 1
                elif T[k] < T[k1]:
                    T[k] = T[k1]
        print(T[k])
if __name__ == '__main__':
    main()