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: # -*- 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()

Python: n = int(input())
xs = []
ys = []
for _ in range(n):
    x = input()
    y = input()
    xs.append(x)
    ys.append(y)

for i in range(n):
    a, b = xs[i], ys[i]
    L = []
    for bk in b:
        bgn_idx = 0
        for j, cur_idx in enumerate(L):
            chr_idx = a.find(bk, bgn_idx) + 1
            if not chr_idx:
                break
            L[j] = min(cur_idx, chr_idx)
            bgn_idx = cur_idx
        else:
            chr_idx = a.find(bk, bgn_idx) + 1
            if chr_idx:
                L.append(chr_idx)
    print(len(L))

Python: q = int(input())
for i in range(q):
    x = input()
    y = input()
    n = len(x)
    m = len(y)
    d = [[0 for _ in range(m+1)] for _ in range(n+1)]
    for i in range(n):
        for j in range(m):
            if x[i] == y[j]:
                d[i+1][j+1] = d[i][j]+1
            else:
                d[i+1][j+1] = max(d[i+1][j],d[i][j+1])
    print(d[n][m])

Python: from bisect import bisect_left
q = int(input())
for _ in [0]*q:
    s1, s2 = input(), input()
    l1, l2 = len(s1), len(s2)

    p = []
    for i, c in enumerate(s1):
        s = 0
        while True:
            j = s2[s:].find(c)
            if j == -1:
                break
            p.append((i, s+j))
            s += j+1

    lis = []
    for _, y in sorted(p, key=lambda x: (x[0], -x[1])):
        i = bisect_left(lis, y)
        if len(lis) <= i:
            lis.append(y)
        else:
            lis[i] = y
    print(len(lis))

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: from collections import defaultdict
INF = 10000
def lcs(s1, s2):
    c = defaultdict(list)
    for i, s in enumerate(s1):
        c[s].append(i)
    for s in set(s2):
        c[s].append(INF)
    def g(li, a):
        for i in li:
            if i >= a:
                return i
        return -1
    dp = []
    for s2_k in s2:
        bgn_idx = 0
        for i, cur_idx in enumerate(dp):
            chr_idx = g(c[s2_k], bgn_idx)
            if chr_idx == INF:
                continue
            dp[i] = min(cur_idx, chr_idx + 1)
            bgn_idx = cur_idx
        else:
            chr_idx = g(c[s2_k], bgn_idx)
            if chr_idx != INF:
                dp.append(chr_idx + 1)
    return len(dp)
def solve():
    N = int(input())
    for _ in range(N):
        x = input()
        y = input()
        print(lcs(x, y))
solve()