Go: package main

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

// define
var (
	sc = bufio.NewScanner(os.Stdin)
)

func bordersInt(in_map [][]int, invalid int) [][]int{
	H, W := len(in_map), len(in_map[0])
	out_map := make([][]int, H+2)
	for h:=0; h<H+2; h++ {
		out_map[h] = make([]int, W+2)
		for w:=0; w<W+2; w++ {
			out_map[h][w] = invalid
		}
	}
	for h:=0; h<H; h++{
		for w:=0; w<W; w++{
			out_map[h+1][w+1] = in_map[h][w] 
		}
	}
	return out_map
}

func bordersString(in_map [][]string, invalid string) [][]string{
	H, W := len(in_map), len(in_map[0])
	out_map := make([][]string, H+2)
	for h:=0; h<H+2; h++ {
		out_map[h] = make([]string, W+2)
		for w:=0; w<W+2; w++ {
			out_map[h][w] = invalid
		}
	}
	for h:=0; h<H; h++{
		for w:=0; w<W; w++{
			out_map[h+1][w+1] = in_map[h][w] 
		}
	}
	return out_map
}

func scanIntLine(len int) []int{
	arr := make([]int, len)
	for i:=0; i<len; i++{
		sc.Scan()
		tmp, err := strconv.Atoi(sc.Text())
		if err == nil{
			arr[i] = tmp
		}
	}
	return arr
}

func scanStringLine(len int) []string{
	arr := make([]string, len)
	for i:=0; i<len; i++{
		sc.Scan()
		arr[i] = sc.Text()
	}
	return arr
}

func scanIntSplit(len int) []int{
	arr := make([]int, len)
	sc.Scan()
	for i, v := range strings.Split(sc.Text(), " "){
		tmp, err := strconv.Atoi(v)
		if err == nil{
			arr[i] = tmp
		}
	}
	return arr
}

func maxInt(args... int) int{
	sort.Ints(args)
	return args[len(args)-1]
}

func main(){
	var n int 
	fmt.Scan(&n)
	dp := make([][]int, 1003)
	for i:=0; i<1003; i++ {
		dp[i] = make([]int, 1003)
	}
	input_lines := scanStringLine(2*n)
	for i:=0; i<n; i++ {
		S, T := input_lines[2*i], input_lines[2*i+1]
		lenS, lenT := len(S), len(T)
		for i:=1; i<lenS+1; i++ {
			for j:=1; j<lenT+1; j++ {
				if S[i-1] == T[j-1] {
					dp[i][j] = maxInt(dp[i-1][j-1]+1, dp[i-1][j], dp[i][j-1])
				} else {
					dp[i][j] = maxInt(dp[i-1][j], dp[i][j-1])
				}
			}
		}
		fmt.Println(dp[lenS][lenT])
	}
}

Python: # coding: utf-8

def lcs(str1, str2):
    # dp[i][j]: str1のi番目までとstr2のj番目までを使って作れるlcs
    dp = [[0 for _ in range(len(str2)+10)] for _ in range(len(str1)+10)]
    # 計算量は1000*1000=10^6なんだけど時間切れ？
    for i in range(0,len(str1)):
        for j in range(0,len(str2)):
            v = max(dp[i+1][j],dp[i][j+1])
            if str1[i] == str2[j]:
                dp[i+1][j+1] = max(v,dp[i][j] + 1)
            else:
                dp[i+1][j+1] = max(v,dp[i][j])
    return dp[len(str1)][len(str2)]

# てか、普通のdpじゃ通らないってどんだけシビアなんだ
def lcs_another(str1, str2):
    # str1の中の文字列とstr2の中の文字列が一致したらその位置から先を＋１するだけ
    # なんか自然には思い浮かばないなあ
    dp = [0 for _ in range(len(str2)+10)]
    for c1 in str1:
        tmp = dp[:]
        for i, c2 in enumerate(str2):
            if c1 == c2:
                dp[i+1] = tmp[i]+1
            elif dp[i+1] < dp[i]:
                dp[i+1] = dp[i]
    return dp[len(str2)]

p = int(input().rstrip())
for _ in range(p):
    line1 = input().rstrip()
    line2 = input().rstrip()
    print(lcs_another(line1,line2))

Python: MAX = 1005
n = int(input())
dp = [[0 for j in range(MAX)] for i in range(MAX)]
for _ in range(n):
    X = input()
    Y = input()
    len_X = len(X)
    len_Y = len(Y)

    for i in range(len_X):
        for j in range(len_Y):
            dp[i + 1][j + 1] = dp[i][j] + 1 if X[i] == Y[j] else max(dp[i][j + 1], dp[i + 1][j])
    print(dp[len_X][len_Y])

Python: n=int(input())

l=[]

for i in range(n):
	a=al.list(input())
	b=bl.list(input())
	dp=[[0 for i in range(len(b))] for j in range(len(a))]

	if a[0]==b[0]:
		dp[0][0]=1
	for i in range(1,len(a)):
		if a[i]==b[0]:
			dp[i][0]=1
		else:
			dp[i][0]=dp[i-1][0]
	for i in range(1,len(b)):
		if a[0]==b[i]:
			dp[0][i]=1
		else:
			dp[0][i]=dp[0][i-1]
	for i in range(1, len(a)):
		for j in range(1, len(b)):
			if a[i]==b[j]:
				dp[i][j]=dp[i-1][j-1]+1
			else:
				dp[i][j]=max(dp[i-1][j-1],dp[i-1][j],dp[i][j-1])

	l.append(dp[len(a)-1][len(b)-1])

for i in l:
	print(l)

Python: # -*- coding: utf-8 -*-
import sys
from itertools import product
sys.setrecursionlimit(100000)

N = int(input())

def calc_LCS(n, m):
    if n == 0 or m == 0:
        return 0
    elif X[n] == Y[m]:
        LCS[n][m] = LCS[n-1][m-1] + 1
        return LCS[n][m]
    else:
        LCS[n][m] = max(LCS[n-1][m], LCS[n][m-1])
        return LCS[n][m]
        

for _ in range(N):
    X = ["  "] + list(input())
    Y = [" "] + list(input())
    LCS = [[0 for _ in range(len(Y))] for _ in range(len(X))]
    max_ = 0
    for n, m in product(range(len(X)), range(len(Y))):        
        if n == 0 or m == 0:
            pass

        elif X[n] == Y[m]:
            LCS[n][m] = LCS[n-1][m-1] + 1
            
            max_ =  max(LCS[n][m], max_)
        else:
            LCS[n][m] = max(LCS[n-1][m], LCS[n][m-1])
            max_ = max(LCS[n][m], max_)
    print(max_)

Python: import sys

def dp_init(m, n):
    return [[0] * n] * m

def solve(str_a, str_b):
    dp = dp_init(len(str_a), len(str_b))
    return rec(len(str_a), len(str_b), str_a, str_b, dp)

def rec(i, j, str_a, str_b, dp):
    if i == 0 or j == 0:
        return 0
    if dp[i-1][j-1] > 0:
        return dp[i-1][j-1]
    if str_a[i-1] == str_b[j-1]:
        dp[i-1][j-1] = rec(i-1, j-1, str_a, str_b, dp) + 1
        return dp[i-1][j-1]
    dp[i-1][j-1] = max(rec(i, j-1, str_a, str_b, dp), rec(i-1, j, str_a, str_b, dp))
    return dp[i-1][j-1]

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))

Python: def Ics(x, y):
    a = len(x)
    b = len(y)
    c1 = [0] * (b + 1)

    for i in range(a):
        d = x[i]
        c2 = c1[:]
        for j in range(b):
            if d == y[j]:
                c1[j + 1] = c2[j] + 1
            elif c1[j + 1] < c1[j]:
                c1[j + 1] = c1[j]
    return (c1[-1])

q = int(input().rstrip())
r = []
for k in range(q):
    s1 = input().rstrip()
    s2 = input().rstrip()
    r.append(Ics(s1, s2))

print(*r, sep = "\n")

Python: def common():
   X = raw_input()
   Y = raw_input()
 
   s = [0 for i in range(len(Y)+1)]

   for j in range(0, len(X)):
      t = s + []
      for k in range(0, len(Y)):
         if X[j] == Y[k]:
            s[k+1] = t[k] + 1
         elif s[k+1] < s[k]:
            s[k+1] = s[k]
 
   return s[-1]

q = input()
for l in range(0, q):
   common()

Python: import itertools
import numpy
import time

c = [[0]*1001 for _ in range(1001)]

def make_lcs(lhs, rhs):
    llen = len(lhs)
    rlen = len(rhs)
    for l_i, r_i in itertools.product(range(llen), range(rlen)):
            c[l_i + 1][r_i + 1] = max(c[l_i][r_i + 1], c[l_i + 1][r_i]) if lhs[l_i] != rhs[r_i] else c[l_i][r_i] + 1
    print(c[llen][rlen])


if __name__ == '__main__':
    start = time.time()
    n = int(input())
    for _ in range(n):
        lhs = [i for i in input().rstrip()]
        rhs = [i for i in input().rstrip()]
        make_lcs(lhs, rhs)
    end = time.time() - start
    print('elapsed time: {}'.format(end))

Python: def lcs(str1,str2):
    c=[[0 for _ in range(1001)] for _ in range(1001)]
    m=len(str1)
    n=len(str2)
    maxl=0
    str1=" "+str1
    str2=" "+str2

    i=1
    j=1
    while(i<=m):
        while(j<=n):
            if(str1[i]==str2[j]):
                c[i][j]=c[i-1][j-1]+1
              #  print(c[i][j])
            else:
                c[i][j]=max(c[i-1][j],c[i][j-1])
            maxl=max(maxl,c[i][j])
            j+=1
        i+=1
        j=0

    return maxl

def main():
    n=int(input())
    i=0
    while(i<n):
        str1=str(input())
        str2=str(input())
        print(int(lcs(str1,str2)))
        i+=1

main()