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(){
	buf := make([]byte, 0)
    sc.Buffer(buf, 1000000009)
	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: def lcs(X, Y):
    costs = [0]
    for c in Y:
        for i in range(len(costs) - 1, -1, -1):
            tmp = X.find(c, costs[i])
            if tmp + 1:
                if i + 1 < len(costs):
                    costs[i + 1] = min(costs[i + 1], tmp + 1)
                else:
                    costs.append(tmp + 1)
    return len(costs) - 1

n = int(input())
for _ in range(n):
    X, Y = (input() for _ in range(2))
    print(lcs(X, Y))

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+=[len(z)]
print('\n'.join(map(str,a)))

Python: import sys

def lcm(c,i, j):
    if c[i][j]>0: return c[i][j]        
    if i==0 or j==0:
        return 0
    elif x[i]==y[j]:
        c[i][j] = lcm(c,i-1,j-1)+1
        return c[i][j]
    else:
        c[i][j] = max(lcm(c,i,j-1), lcm(c,i-1,j))
        return c[i][j]

for _ in range(int(sys.stdin.readline())):
    x = sys.stdin.readline()
    y = sys.stdin.readline()
    c = [[0 for _ in range(len(y)+1)] for _ in range(len(x)+1)] 
    print(lcm(c,len(x)-1,len(y)-1))

Python: def findlcs(x, y):
    dp = [[0]*(len(y)+1) for i in range(len(x)+1)]

    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)]


q = int(input())
for k in range(q):
    X = input()
    Y = input()
    print(findlcs(X, Y))

Python: 
def f(x,y):
	list=[0]
	for z in y:
		for i in range(len(list)-1,-1,-1):
			tmp=x.find(z,list[i])+1
			if tmp:
				if i+1 < len(list):
					list[i+1]=min(list[i+1],tmp)
				else:
					list.append(tmp)
	return len(list)-1
 
n=int(input())
for i in range(n):
	x=input()
	y=input()
	print(f(x,y))

Python: pcsl = [[0 for i in range(1001)] for j in range(1001)]

def lcs(x, y):
    lx = len(x)
    ly = len(y)
    for i in range(lx):
        for j in range(ly):
            if x[i] == y[j]:
                pcsl[i][j] = pcsl[i - 1][j - 1] + 1
            elif pcsl[i - 1][j] > pcsl[i][j - 1]:
                pcsl[i][j] = pcsl[i - 1][j]
            else:
                pcsl[i][j] = pcsl[i][j - 1]
    print(pcsl[i][j])


q = int(input())

for i in range(q):
    ax = input()
    ay = input()
    lcs(ax, ay)

Python: a=[]
for _ in[0]*int(input()):
 X,z=input(),[]
 for y in input():
  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+=[len(z)]
print(*a,sep='\n')

Python: def Ics(X, Y):
    m = len(X)
    n = len(Y)
    c1, 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(n):
    s1 = input().rstrip()
    s2 = input().rstrip()
    t.append(Ics(s1, s2))
print(*t, sep="\n")

Python: def common():
   X = raw_input()
   Y = raw_input()
             
   for i in range(0, len(Y)+1):
      s[i] = 0
             
   for j in range(0, len(X)):
      t = s + []
      for k in range(0, len(Y)):
         if s[j] == j[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: n = int(input())

for k in range(n):
    a = input()
    b = input()
    len_a, len_b = len(a), len(b)
    table = [[0] * (len_b +1) for i in range(len_a + 1)]
    
    for i in range(1,len_a+1):
        for j in range(1,len_b+1):
            if a[i-1] == b[j-1]:
                table[i][j] = table[i-1][j-1] + 1
            else:
                table[i][j] = max(table[i-1][j],table[i][j-1])
    print(table[len_a][len_b])

Python: def calc(x,y):
    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]
    return dp1[-1]

q = int(input().rstrip())
ans = []
for i in range(q):
    x = input()
    y = input()
    ans.append(calc(x,y))
print(*ans, sep="\n")

Python: import sys

n=int(input())

for _ in range(n):
	x=sys.stdin.readline().rstrip('\r\n')
	y=sys.stdin.readline().rstrip('\r\n')
	
	list=[0]
	for z in y:
		for i in range(len(list)-1,-1,-1):
			tmp=x.find(z,list[i])
			if tmp+1:
				if i+1<len(list):
					list[i+1]=min(tmp+1,list[i+1])
				else:
					list.append(tmp+1)
print(len(list)-1)

Python: a = (int)(input())
for i in range(a):
    str1 = input()
    str2 = input()
    size1 = len(str1)
    size2 = len(str2)
    dp = [[0 for j in range(size2+1)] for k in range(size1+1)]

    for j in range(1,size1+1):
        for k in range(1,size2+1):
            if str1[j-1]==str2[k-1]:
                dp[j][k] = max([dp[j-1][k],dp[j][k-1],dp[j-1][k-1]+1])
            else:
                dp[j][k] = max([dp[j-1][k],dp[j][k-1],dp[j-1][k-1]])

    print(dp[size1][size2])

Python: for _ in range(int(input())):
    a = input()
    b = input()
    if len(a) < len(b):
        a, b = b, a
    indices = []
    for cb in b:
        bgn_idx = 0
        for i, cur_idx in enumerate(indices):
            chr_idx = a.find(cb, bgn_idx) + 1
            if not chr_idx:
                break
            if chr_idx < cur_idx:
                indices[i] = chr_idx
            bgn_idx = cur_idx
        else:
            chr_idx = a.find(cb, bgn_idx) + 1
            if chr_idx:
                indices.append(chr_idx)
    print(len(indices))