Go: package main

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

var (
	nstr   func() string
	stdout *bufio.Writer
)

func init() {
	nstr = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func main() {
	defer stdout.Flush()

	n := nint()
	xList := make([]string, n)
	yList := make([]string, n)

	for i:=0;i<n ;i++  {
		xList[i] = nstr()
		yList[i] = nstr()
	}

	for i := 0; i<n	; i++  {
		fmt.Println(lcs(xList[i], yList[i]))
	}

}

func lcs(x string, y string) int{
	var m = len(x)
	var n = len(y)

	c := make([][]int, m+1)
	for i:= range c{
		c[i] = make([]int, n+1)
	}
	for i:=	1;i<=m ;i++  {
		for j:=1;j<=n ;j++  {
			if x[i-1] == y[j-1]{
				c[i][j] = c[i-1][j-1] + 1
			}else{
				c[i][j] = int(math.Max(float64(c[i-1][j]), float64(c[i][j-1])))
			}


		}
	}
	return c[m][n]

}


func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+11))
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

func nint64() int64 {
	i, err := strconv.ParseInt(nstr(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func nint() int {
	return int(nint64())
}

func getIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = nint()
	}
	return b
}

func getStringSlice(n int) []string {
	b := make([]string, n)
	for i := 0; i < n; i++ {
		b[i] = nstr()
	}
	return b
}

func gcd(x, y int) int {
	if y == 0 {
		return x
	}
	return gcd(y, x%y)
}

func lcm(x, y int) int {
	return x * y / gcd(x, y)
}

func contains(s []int, e int) bool {
	for _, a := range s {
		if a == e {
			return true
		}
	}
	return false
}

func bin(i int, prefix bool) string {
	i64 := int64(i)

	if prefix {
		return "0b" + strconv.FormatInt(i64, 2)
	} else {
		return strconv.FormatInt(i64, 2)
	}
}

func strReverse(s string) string {
	runes := []rune(s)
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}

	return string(runes)
}

Python: def lcs_hs(s1, s2):
    from bisect import bisect_left

    s2 = s2[::-1]
    lis, result = [], 0
    append = lis.append

    for c in s1:
        i = s2.find(c)+1
        while i:
            j = bisect_left(lis, -i)
            if j >= result:
                append(-i)
                result += 1
            else:
                lis[j] = -i
            i = s2.find(c, i)+1

    return result


print(*(lcs_hs(input(), input()) for _ in [0]*int(input())), sep="\n")

Python: #dj 16D8101012J ito jun
n = int(input())
for _ in range(n):
    a = input()
    b = input()
    na=len(a)
    nb=len(b)
    array = [[0 for i in range(nb+1)] for j in range(na+1)]
    for i in range(1,na+1):
        for j in range(1,nb+1):
            c = 0
            if a[i-1] == b[j-1]:
                array[i][j]=array[i-1][j-1]+1
            else:
                array[i][j] = max(array[i-1][j],array[i][j-1])
    print(array[na][nb])

Python: n=int(input())
x=[0 for i in range(n)]
y=[0 for i in range(n)]
for i in range(n):
    x[i]=input()
    y[i]=input()

for i in range(n):
    X=list(x[i])
    Y=list(y[i])
    a=[int(0) for i in range(len(X))]
    for j in range(len(X)):
        b=-1
        for l in range(j,len(X)):
            for k in range(len(Y)):
                if X[l]==Y[k] and b<k:
                    b=k
                    a[j]+=1
                    break
                
    print(max(a))

Python: import sys
sys.setrecursionlimit(200000)
from functools import lru_cache
from collections import defaultdict
from bisect import bisect_left, bisect, insort_left, insort
q = int(input())
for _ in range(q):
    x = input()
    y = input()
    len_x = len(x)
    len_y = len(y)
    if len_x < len_y:
        len_x, len_y = len_y, len_x
        x, y = y, x
    c = defaultdict(list)
    for i, s in enumerate(x):
        c[s].append(i)
    ans = 0
    @lru_cache(maxsize=1000)
    def f(x_i, y_i, cnt):
        if x_i >= len_x or y_i >= len_y:
            global ans
            if ans < cnt:
                ans = cnt
            return
        f(x_i, y_i + 1, cnt)
        s = bisect_left(c[y[y_i]], x_i)
        if s < len(c[y[y_i]]) and c[y[y_i]][s] < len_x:
            f(c[y[y_i]][s] + 1, y_i + 1, cnt + 1)
    f(0, 0, 0)
    print(ans)

Python: def lcs(str1,str2):
    c=[[0 for _ in range(1000)] for _ in range(1000)]
    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: 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+=[z]
print('\n'.join(map(str,map(len,a))))

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)



def solve():

    N = int(input())

    for _ in range(N):

        x = input()

        y = input()

        print(lcs(x, y))



if __name__ == '__main__':

    solve()

Python: # 38

import sys


def lcs(X, Y):
    l_x = len(X)
    l_y = len(Y)
    # dp[i][j] : Xのi文字目、Yのj文字目までから構成される最長部分列数
    dp = [[0] * (l_y+1) for _ in range(l_x+1)]
    for i in range(l_x):
        for j in range(l_y):
            if X[i] == Y[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 lcs_s(X, Y):
    L = []
    for yk in Y:
        bgn_idx = 0
        for i, cur_idx in enumerate(L):
            chr_idx = X.find(yk, bgn_idx) + 1
            if not chr_idx:
                break
            L[i] = min(cur_idx, chr_idx)
            bgn_idx = cur_idx
        else:
            chr_idx = X.find(yk, bgn_idx) + 1
            if chr_idx:
                L.append(chr_idx)
    return len(L)


Q = int(input())
for _ in range(Q):
    X = sys.stdin.readline().rstrip()
    Y = sys.stdin.readline().rstrip()
    print(lcs_s(X, Y))

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-1 == 0 or j-1 == 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
        print("(%d, %d) : %d" % (i-1, j-1, dp[i-1][j-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))
    print("(%d, %d) : %d" % (i-1, j-1, dp[i-1][j-1]))
    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))