Go: package main

import (
	"fmt"
)

func main() {
	var q int
	fmt.Scan(&q)

	for i := 0; i < q; i++ {
		var x, y string
		fmt.Scan(&x)
		fmt.Scan(&y)

		xs := []rune(x)
		ys := []rune(y)

		xn := len(xs)
		yn := len(ys)
		dp := make([][]int, xn+1)
		for j := 0; j <= xn; j++ {
			dp[j] = make([]int, yn+1)
		}

		for j := 1; j <= xn; j++ {
			for k := 1; k <= yn; k++ {
				dp[j][k] = max(dp[j-1][k], dp[j][k-1])
				if xs[j-1] == ys[k-1] {
					dp[j][k] = max(dp[j][k], dp[j-1][k-1] + 1)
				} else {
					dp[j][k] = max(dp[j][k], dp[j-1][k-1])
				}
			}
		}
		fmt.Println(dp[xn][yn])
	}
}

func max(a, b int) int {
	if a < b {
		return b
	} else {
		return a
	}
}

Python: def lcs(X,Y):
    Xlength = len(X)
    Ylength = len(Y)
    # print(X,Y)
    if Xlength == 0 or Ylength == 0:
        c[Xlength][Ylength] = 0
        return c[Xlength][Ylength]



    if X[Xlength -1] == Y[Ylength -1]:
        if c[Xlength-1][Ylength-1] is not None:
            c[Xlength][Ylength] = c[Xlength-1][Ylength-1]+1
        else:
            c[Xlength][Ylength] = lcs(X[:Xlength-1], Y[:Ylength-1])+1
    else:
        if c[Xlength-1][Ylength] is not None and c[Xlength][Ylength-1] is not None:
            c[Xlength][Ylength] = max(c[Xlength][Ylength-1],c[Xlength-1][Ylength])
        elif c[Xlength-1][Ylength] is not None:
            c[Xlength][Ylength] = max(lcs(X,Y[:Ylength-1]),c[Xlength-1][Ylength])
        elif c[Xlength][Ylength-1] is not None:
            c[Xlength][Ylength] = max(c[Xlength][Ylength-1],lcs(X[:Xlength-1],Y))
        else:
            c[Xlength][Ylength] = max(lcs(X,Y[:Ylength-1]),lcs(X[:Xlength-1],Y))

    return c[Xlength][Ylength]


n = int(input())
X = []
Y = []
c = [[None]*1001 for i in range(1001)]


for i in range(n):
    X.append(input())
    Y.append(input())

for i in range(n):
    # print(i)
    print(lcs(X[i],Y[i]))
    c = [[None]*1001 for i in range(1001)]

Python: q = int(input())
for i in range(q):
    x = input()
    y = input()
    n = len(x)
    m = len(y)
    dp1 = [0]*(m+1)
    for i in range(n):
        dp2 = dp1[:]
        for j in range(m):
            if x[i] == y[j]:
                dp1[j+1] = dp2[j]+1
            elif dp1[j+1] < dp1[j]:
                dp1[j+1] = dp1[j]
    print(dp1[-1])

Python: n=int(input())

al=[]
bl=[]

for i in range(n):
	al.append(list(input()))
	bl.append(list(input()))

for i in range(n):
	a=al.pop(0)
	b=bl.pop(0)
	dp=[[0 for i in range(len(b))] for j in range(len(a))]

	if a[0]==b[0]:
		dp[0][0]=1
	for i in range(1,len(a)):
		if a[i]==b[0]:
			dp[i][0]=1
		else:
			dp[i][0]=dp[i-1][0]
	for i in range(1,len(b)):
		if a[0]==b[i]:
			dp[0][i]=1
		else:
			dp[0][i]=dp[0][i-1]
	for i in range(1, len(a)):
		for j in range(1, len(b)):
			if a[i]==b[j]:
				dp[i][j]=dp[i-1][j-1]+1
			else:
				dp[i][j]=max(dp[i-1][j-1],dp[i-1][j],dp[i][j-1])

	print(dp[len(a)-1][len(b)-1])

Python: import sys
readline = sys.stdin.readline
for _ in range(int(input())):
    a = readline().strip()
    b = readline().strip()
    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))

Python: from sys import stdin

X = [ 0 for i in range(1000) ]
Y = [ 0 for i in range(1000) ]
Z = [[0 for i in range(1000)]for i in range(1000)]

def getLCS(l) :
	xlen = len(X[l])
	ylen = len(Y[l])

	for i in range(1,xlen+1) :
		for j in range(1,ylen+1) :
			a = 1 if X[l][i-1] == Y[l][j-1] else 0
			Z[i][j] = max(Z[i-1][j-1] + a, Z[i-1][j], Z[i][j-1])

	return Z[xlen][ylen]

n = int(input())
for l in range(n) :
	X[l] = stdin.readline().strip()
	Y[l] = stdin.readline().strip()
	print(getLCS(l))

Python: 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]
 print(len(z))

Python: q = int(input())

l = []
x = ""
y = ""

for i in range(q):
    x = input()
    y = input()
 
    yLen = len(y)
    xLen = len(x)
    l = [[0] * (xLen + 1) for j in range(yLen + 1)]

    for j in range(1, yLen + 1):
        for k in range(1, xLen + 1):
            if x[k - 1] == y[j - 1]:
                l[j][k] = 1 + l[j - 1][k - 1]
            else:
                if l[j][k - 1] > l[j - 1][k]:
                    l[j][k] = l[j][k - 1]
                else:
                    l[j][k] = l[j - 1][k]
 
    print(l[yLen][xLen])

Python: q = int(input())

for __ in range (q):

    S1 = input()
    S2 = input()
    dp = [[0 for i in range(len(S2)+1+10)] for j in range(len(S1)+1+10)]


    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]+1,dp[i+1][j]+1)
            else:
                dp[i+1][j+1] = max(dp[i+1][j],dp[i][j+1])

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

Python: import sys
input = lambda: sys.stdin.readline().rstrip()

def lcs(x, y):
    dp = [0  for _ in range(len(y)+1)]
    for i in range(len(x)):
        tmp = dp[:]
        num = x[i]
        for j in range(len(y)):
            if num == y[j]:
                dp[j+1] = tmp[j] + 1
            elif dp[j+1] < dp[j]:
                dp[j+1] = dp[j]  
    return dp[-1]

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

Python: def main():
    n = int(input())
    for i in range(n):
        a = input()
        b = input()
        na=len(a)
        nb=len(b)
        array = [[1]*nb]*na
        #array = [[0 for i in range(nb)] for j in range(na)]
        print(array)
        for i in range(na):
            for j in range(nb):
                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:
                    c = 0
                    if a[i] == b[j]:
                        c = 1
                    array[i][j] = array[i-1][j-1]+c 
                    max(
                            array[i-1][j],
                            array[i][j-1],
                            array[i-1][j-1]+c)
        print(array[na-1][nb-1])
if __name__ == "__main__":
    main()

Python: import sys


def lcs(x, y):
    # Creating len(x + 1) * len(y + 1) table
    x = ' ' + x  # Add Space
    y = ' ' + y  # Add Space
    len_x = len(x)
    len_y = len(y)
    table = []
    for _ in range(len_y):
        table.append([0] * len_x)

    maxl = 0
    for i, x_ch in enumerate(x):
        if i == 0: continue
        for j, y_ch in enumerate(y):
            if j == 0: continue
            if x[i] == y[j]:
                table[j][i] = table[j - 1][i - 1] + 1
            else:
                table[j][i] = max(table[j - 1][i], table[j][i - 1])
            maxl = max(maxl, table[j][i])

    return maxl


if __name__ == "__main__":
    lines = [line.strip() for line in sys.stdin.readlines()[1:]]
    for sequence_pair in zip(lines[::2], lines[1::2]):
        print(lcs(*sequence_pair))

Python: def lcs(X, Y):
    m, n = len(X), len(Y)
    c = [[0 for i in range(n+1)] for j in range(m+1)]
    for i in range(1, m+1):
        for j in range(1, n+1):
            if X[i-1] == Y[j-1]:
                c[i][j] = c[i-1][j-1] + 1
            else:
                c[i][j] = max(c[i-1][j], c[i][j-1])
    return c[m][n]

q = int(input())
for i in range(q):
    X = input()
    Y = input()
    print(lcs(X, Y))