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: import sys
readline = sys.stdin.readline
from collections import defaultdict
from bisect import bisect_left, bisect, insort_left, insort
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)
    dp = []
    for s2_k in s2:
        bgn_idx = 0
        for i, cur_idx in enumerate(dp):
            chr_idx = c[s2_k][bisect_left(c[s2_k], bgn_idx)]
            if chr_idx == INF:
                break
            dp[i] = min(cur_idx, chr_idx + 1)
            bgn_idx = cur_idx
        else:
            chr_idx = c[s2_k][bisect_left(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 = readline().strip()
        y = readline().strip()
        print(lcs(x, y) if len(x) > len(y) else lcs(y, x))
solve()

Python: q = int(input().rstrip())
for i in range(q):
    x = input().rstrip()
    y = input().rstrip()
    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]
    print(dp1[-1])

Python: q = int(input())


for __ in range (q):

    S1 = input()
    S2 = input()
    dp = [[0 for i in range(len(S2)+1)] for j in range(len(S1)+1)]


    for i in range (len(S1)):
        for j in range (len(S2)):
            if S1[i] != S2[j]:
                dp[i+1][j+1] = max(dp[i+1][j],dp[i][j+1])
            else:
                dp[i+1][j+1] = (dp[i][j]+1)

    print(dp[len(S1)][len(S2)])

Python: n = int(input())

for i in range(n):
    s = list(input())
    t = list(input())
    dp = [[0 for j in range(len(s)+1)] for k in range(len(t)+1)]

    for j in range(len(s)):
        for k in range(len(t)):
            if s[j]==t[k]:
                dp[k+1][j+1] = max(dp[k][j]+1,dp[k+1][j+1])
            else:
                dp[k+1][j+1] = max(dp[k+1][j+1],dp[k+1][j])
                dp[k+1][j+1] = max(dp[k+1][j+1],dp[k][j+1])
    print(dp[len(t)][len(s)])

Python: # -*- coding: utf-8 -*-
def lcs(x, y):
    dp = {(0, 0): 0}
    for i in range(1, len(x) + 1):
        dp[(i, 0)] = 0
    for j in range(1, len(y) + 1):
        dp[(0, j)] = 0
    for i in range(1, len(x) + 1):
        for j in range(1, len(y) + 1):
            if x[i - 1] == y[j - 1]:
                dp[(i, j)] = dp[(i - 1, j - 1)] + 1
            else:
                dp[(i, j)] = max(dp[(i - 1, j)], dp[(i, j - 1)])

    return dp[(len(x), len(y))]


if __name__ == '__main__':
    import sys
    q = int(sys.stdin.readline().strip())
    for i in range(q):
        x = sys.stdin.readline().strip()
        y = sys.stdin.readline().strip()
        print(lcs(x, y))

Python: def solver(str_1 ,str_2):
  dp = [[0] * (len(str_2) + 1) for i in range(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: def Ics(X, Y):
    m = len(X)
    n = len(Y)
    c1 = [0] * (n + 1)
    c2 = [0] * (n + 1)
    for i in range(m):
        d = X[i]
        for j in range(n):
            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())
t = []
for i in range(q):
    s1 = input().rstrip()
    s2 = input().rstrip()
    t.append(Ics(s1, s2))
print(*t, sep="\n")

Python: def f(i,j):
    if i == 0 or j == 0:
        if s1[i] == s2[j]:
            x[i][j] = 1
        else:
            if i == 0:
                x[i][j] = x[i][j-1]
            else:
                x[i][j] = x[i-1][j]
    elif s1[i] == s2[j]:
        x[i][j] = max(x[i-1][j-1]+1,x[i][j-1],x[i-1][j])
    else:
        x[i][j] = max(x[i-1][j-1],x[i][j-1],x[i-1][j])

n = int(input())
for i in range(n):
    s1 = input()
    s2 = input()
    x = [[0 for j in range(len(s2))]for k in range(len(s1))]
    for j in range(len(s1)):
        for k in range(len(s2)):
            f(j,k)
            
    print(x[len(s1)-1][len(s2)-1])