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 answer(X, Y):
    m, n = len(X), len(Y)
    C = [[] * (n + 1) for _ in range(m + 1)]
    for i in range(m + 1):
        C[i][0] = 0
    for j in range(n + 1):
        C[0][j] = 0

    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][j -1], C[i -1][j])
    return C[m][n]


if __name__ == '__main__':
    q = int(input())
    for _ in range(q):
        X = input()
        Y = input()
        print((X, Y))

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

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

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 lcss(x,y):
    
    lcs = [0]*(len(x)+1)
    for i in range(len(y)):
        w1 = y[i]
        lcs_2 = lcs[:]
        for j in range(len(x)):
            if x[j] == w1:
                lcs[j+1] = lcs_2[j] + 1  
            elif lcs[j+1] < lcs[j]:
                lcs[j+1] = lcs[j]
    return lcs[-1]

ret = []
for i in range(q):
    x = input()
    y = input()
    ret.append(lcss(x,y))
print(*ret,sep= "\n")

Python: from sys import stdin
from collections import deque
def search(A,B):
    N_A,N_B=len(A),len(B)
    BB=[0]*N_B
    # matrix=[[0 for j in range(N_B)] for i in range(N_A)]
    for i in range(1,N_A):
        AA=BB[:]
        for j in range(1,N_B):
            if A[i]==B[j]:
                BB[j]=AA[j-1]+1
            elif BB[j-1]>BB[j]:
                # BB[j]=BB[j-1]
                BB[j] = max(BB[j - 1], AA[j])
            # else:
            #     BB[j]=max(BB[j-1],AA[j])
    return (BB[-1])
N=int(input())
for i in range(N):

    A=deque(list(stdin.readline().strip()))
    B=deque(list(stdin.readline().strip()))
    A.appendleft(0)
    B.appendleft(0)
    print(search(A,B))

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

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

Python: from collections import defaultdict


def lcs(x, y):
    dp = [defaultdict(int) for _ in range(len(x) + 1)]
    dp[0] = [0]*(len(y) + 1)
    for i in range(len(x)):
        for j in range(len(y)):
            if x[i] == y[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])
    return dp[len(x)][len(y)]


N = int(input())
for i in range(N):
    x = input()
    y = input()
    print(lcs(x, y))

Python: def lcs(l1,l2):
    dp=[[0 for x in range(len(l2)+1)] for y in range(len(l1)+1)]

    for i in range(1,len(l1)+1):
        for j in range(1,len(l2)+1):
            if l1[i-1]==l2[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(l1)][len(l2)]


a=[]
n=int(input())
for i in range(n):
    l1=list(input())
    l2=list(input())
    a+=[lcs(l1,l2)]

for i in range(n):
    print(a[i])

Python: def longest_common_subseq(S, T):
    if not S and not T: return 0
    len_S, len_T = len(S), len(T)
    dp = [0] * (len_T + 1)
    prev = [0] * (len_T + 1)
    for s in S:
        for j in range(len_T):
            if s == T[j]: dp[j+1] = prev[j] + 1
            elif dp[j] > dp[j+1]: dp[j+1] = dp[j]
        prev = dp[:]
    return dp[len_T]

Q = int(input())
ans = []
for _ in range(Q):
    X = input()
    Y = input()
    ans.append(longest_common_subseq(X, Y))
print(*ans, sep='\n')

Python: q = int(input().rstrip())
data_set = [[[i for i in input().rstrip()],
             [i for i in input().rstrip()]] for i in range(q)]

common_list = [[0] * 2000 for i in range(2000)]


def lcs(X: list, Y: list):
    global common_list
    m, n = len(X), len(Y)
    for i in range(1, m + 1):
        for k in range(1, n + 1):
            if X[i - 1] == Y[k - 1]:
                common_list[i][k] = common_list[i - 1][k - 1] + 1
            elif common_list[i - 1][k] >= common_list[i][k - 1]:
                common_list[i][k] = common_list[i - 1][k]
            else:
                common_list[i][k] = common_list[i][k - 1]
    return common_list[m][n]


for l, r in data_set:
    print(lcs(l, r))