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: def lcs(s1, s2):
    dp = []
    for s2_k in s2:
        bgn_idx = 0
        for i, cur_idx in enumerate(dp):
            chr_idx = s1.find(s2_k, bgn_idx) + 1
            if not chr_idx:
                break
            dp[i] = min(cur_idx, chr_idx)
            bgn_idx = cur_idx
        else:
            chr_idx = s1.find(s2_k, bgn_idx) + 1
            if chr_idx:
                dp.append(chr_idx)
    return len(dp)


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

Python: trial = int(input())
for t in range(trial):
    first = input()
    second = input()
    dp = [[0 for n in range(len(second) + 1)] for m in range(len(first) + 1)]
    for fi in range(len(first) + 1):
        for se in range(len(second) + 1):
            if fi == 0 or se == 0:
                continue
            else:
                if first[fi-1] == second[se-1]:
                    dp[fi][se] = dp[fi-1][se-1] + 1
                else:
                    dp[fi][se] = max(dp[fi-1][se],dp[fi][se-1],dp[fi-1][se-1])
    print(dp[-1][-1])

Python: # -*- coding: utf-8 -*-
def lcs_sol(x, y):
    n = len(x)
    m = len(y)
    dp = [0 for j in range(m + 1)]

    for i in range(1, n + 1):
        dp_prev = dp[:]
        for j in range(1, m + 1):
            if x[i - 1] == y[j - 1]:
                dp[j] = dp_prev[j - 1] + 1
            else:
                dp[j] = max(dp_prev[j], dp[j - 1])

    return dp[m]


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_sol(x, y))

Python: def lcs(x, y):
    a = len(x)
    b = len(y)
    c1 = [0] * (b + 1)
    for i in range(a):
        e1 = x[i]
        c2 = c1[:]#スライス
        for j in range(b):
            if e1 == y[j]:
                c1[j+1] = c2[j] + 1
            elif c1[j+1] < c1[j]:
                c1[j+1] = c1[j]
    return c1[-1]
    
n = int(input().rstrip())#rstripで余計な空白削除
ret = []
for i in range(n):
    s1 = input().rstrip()
    s2 = input().rstrip()
    ret.append(lcs(s1, s2))
print(*ret, sep="\n")

Python: t=int(input())
for _ in range(t):
    s=str(input())
    t=str(input())
    dp = [[0 for i in range(len(t)+1)] for j in range(len(s)+1)]
    for i in range(len(s)):
        for j in range(len(t)):
            if s[i]==t[j]:
                dp[i+1][j+1]=dp[i][j]+1
            else:
                dp[i+1][j+1]=max(dp[i][j+1],dp[i+1][j])
    print(dp[len(s)][len(t)])

Python: 
def LCS(x, y):
    dp = {}
    for i in range(len(x)+1):
        dp[i] = {0: i}
    for j in range(len(y)+1):
        dp[0][j] = j
    
    for i in range(1, len(x)+1):
        for j in range(1, len(y)+1):
            d = 0 if x[i-1] == t[j-1] else 1
            dp[i][j] = min(dp[i-1][j] + 1, dp[i][j-1] + 1, dp[i-1][j-1] + d)
    
    longer = max(len(x), len(y))
    return (longer - dp[len(x)][len(y)])

q = int(raw_input())
for i in range(q):
    X = raw_input()
    Y = raw_input()
    print(LCS(X, Y))

Python: q = int(input())

def lcs(a, b):
    # L[i]はa1~ajとb1~bkから長さがi+1の共通部分列が作れるときのjが取りうる最小値とする
    L = []
    for bk in b:
        bgn_idx = 0 # 検索開始位置
        for i, cur_idx in enumerate(L):
            # bkがbgn_idx以降でaにあれば、そのidx+1かcur_idxの小さい方で更新
            chr_idx = a.find(bk, bgn_idx) + 1
            if not chr_idx:
                break
            L[i] = min(cur_idx, chr_idx)
            bgn_idx = cur_idx
        # 全部まわったということはbkが現在の最長の共通文字列以降にaにあったということ。であれば末尾に追加できる
        else:
            # bkがbgn_idx以降でaにあれば、そのidx+1をLに追加
            chr_idx = a.find(bk, bgn_idx) + 1
            if chr_idx:
                L.append(chr_idx)
    return len(L)

for _ in range(q):
    s = input()
    t = input()
    print(lcs(s, t))

Python: from collections import defaultdict


def longest_common_subsequence(s, t):
    dp = [[0] * (len(t) + 1) for _ in range(len(s) + 1)]
    for i in range(len(s)):
        for j in range(len(t)):
            if s[i] == t[j]:
                dp[i + 1][j + 1] = dp[i][j] + 1
            else:
                dp[i + 1][j + 1] = max(dp[i + 1][j], dp[i][j + 1])
    return dp[-1][-1]


def longest_common_subsequence2(s, t):
    dp = [0 for _ in range(len(t) + 1)]
    for i in range(len(s)):
        tmp = dp[:]
        for j in range(len(t)):
            if s[i] == t[j]:
                dp[j + 1] = tmp[j] + 1
            else:
                dp[j + 1] = max(dp[j + 1], dp[j])
    return dp[-1]


def main():
    n = int(input())
    for _ in range(n):
        X, Y = input(), input()
        print(longest_common_subsequence2(X, Y))


if __name__ == '__main__':
    main()

Python: e=input
a=''
for _ in[0]*int(e()):
 X,z=e(),[]
 for y in e():
  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: num = int(input())
for i in range(num):
    X = " " + input()
    Y = " " + input()
    lx = len(X)
    ly = len(Y)
    T = [0] * ly
    for j in range(1,lx):
        C = T[:]
        for k in range(1,ly):
            k1 = k-1
            if X[j] == Y[k]:
                T[k] = C[k1] + 1
            elif C[k] > T[k1]:
                T[k] = C[k]
            else:
                T[k] = T[k1]
    print(T[k])

Python: def main():
    X=input()
    Y=input()
    dp=[]
    for y in range(len(Y)):
        now=0
        for i  in range(len(dp)):
            d=dp[i]
            if Y[y] in X[now:d]:
                dp[i]=now+X[now:d].index(Y[y])
            now=d+1
        if Y[y] in X[now:]:
            dp.append(now+X[now:].index(Y[y]))
    return len(dp)
for i in range(int(input())):
    print(main())