Go: package main

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

func max(x, y int) int {
	if x < y {
		return y
	} else {
		return x
	}
}

/*********************************************************************
長さmの列X_(m)と長さnの列Y_(n)の最長共通部分列LCSは、
	(1)X[m] == Y[n]ならば、X_(m-1)とY_(n-1)のLCSにX[m]を繋げたもの
	(2)X[m] != Y[n]ならば、X_(m-1)とY_(n)のLCSもしくはX_(m)とY_(n-1)のLCS
	のいずれかのうち長い方

c[m+1][n+1]：c[i][j]にX_(i)とY_(j)のLCSの長さを格納する二次元配列
*********************************************************************/

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Scan()
	n, _ := strconv.Atoi(scanner.Text())
	for i := 0; i < n; i++ {
		scanner.Scan()
		s1 := scanner.Text()
		scanner.Scan()
		s2 := scanner.Text()
		s1, s2 = s1 + " ", s2 + " "
		c := make([][]int, len(s1))
		for i := range c {
			c[i] = make([]int, len(s2))
		}

		LCS := 0

		for i := 1; i < len(s1); i++ {
			for j := 1; j < len(s2); j++ {
				if s1[i] == s2[j] {
					c[i][j] = c[i-1][j-1] + 1
				} else {
					c[i][j] = max(c[i-1][j], c[i][j-1])
				}
				LCS = max(LCS, c[i][j])
			}
		}
		fmt.Println(LCS)
	}
}

Python: from sys import stdin
from functools import lru_cache

@lru_cache(maxsize=None)
def lcs_record(x:chr, Y:str):
    return [0] + [1 if x == v else 0 for v in list(Y)]

def len_of_LCS(X:str ,Y:str):
    len_Y = len(Y)
    p_record = [0]*(len_Y+1)
    for x in list(X):
        c_record = lcs_record(x, Y).copy()
        for i in range(1, len_Y+1):
            if c_record[i] == 1:
                c_record[i] = p_record[i-1] + 1
            else:
                c_record[i] = p_record[i] if p_record[i] > c_record[i-1] else c_record[i-1]
        p_record = c_record
    return c_record[len_Y]

n = int(stdin.readline())
lines = list()
for i in range(n*2):
    lines.append(input().rstrip('\n'))
for i in range(n):
    X = lines[i*2]
    Y = lines[i*2+1]
    print(len_of_LCS(X, Y))

Python: import pprint as p
def main():
    n = int(input())
    result = []
    for i in range(n):
        a = input()
        b = input()
        array = [[0 for i in range(len(b))] for j in range(len(a))]
        for i in range(len(a)):
            if a[i]==b[0]:
                array[i][0]=1
        for j in range(len(b)):
            if b[j]==a[0]:
                array[0][j]=1 

        for i in range(1, len(a)):
            for j in range(1, len(b)):
                c = 0
                if a[i] == b[j]:
                    c = 1
                array[i][j] = max(
                                    array[i-1][j],
                                    array[i][j-1],
                                    array[i-1][j-1]+c)
        print(array[len(a)-1][len(b)-1])
        #p.pprint(array)
        """
    for i in result:
        print(i)
        """
if __name__ == "__main__":
    main()

Python: for _ in range(int(input())):
    X = input()
    Y = input()
    dp = [[0] * (len(Y)+1) for x in range(len(X)+1)]
    for x in range(1, len(X) + 1):
        for y in range(1, len(Y) + 1):
            if X[x-1] == Y[y-1]:
                dp[x][y] = dp[x-1][y-1] + 1
            elif dp[x-1][y] > dp[x][y-1]:
                dp[x][y] = dp[x-1][y]
            else:
                dp[x][y] = dp[x][y-1]
    print(dp[-1][-1])

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

q=int(input())
A=[0 for i in range(q)]
for i in range(q):
    X=input()
    Y=input()
    A[i]=lcs(X,Y)

for i in range(q):
    print(A[i]+1)

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: n=int(input())
ans=[]
for k in range(n):
    s1=input()
    s2=input()
    dp=[[0 for i in range(len(s2)+1)] for j in range(len(s1)+1)]
    for i in range(1,len(s1)+1):
        for j in range(1,len(s2)+1):
            if s1[i-1]==s2[j-1]:
                dp[i][j]=dp[i-1][j-1]+1
            else:
                dp[i][j]=max(dp[i-1][j],dp[i][j-1])


    ans.append(dp[len(s1)][len(s2)])
for a in ans:
    print(a)

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
input:
3
abcbdab
bdcaba
abc
abc
abc
bc

output:
4
3
2

"""
import sys


def lcs(A, B):
    m, n = len(A), len(B)
    count_list = [[0] * (n + 1) for _ in range(m + 1)]

    for i in range(1, m + 1):
        for j in range(1, n + 1):
            if A[i - 1] == B[j - 1]:
                count_list[i][j] = count_list[i - 1][j - 1] + 1
            elif count_list[i - 1][j] >= count_list[i][j - 1]:
                count_list[i][j] = count_list[i - 1][j]
            else:
                count_list[i][j] = count_list[i][j - 1]

    return count_list[m][n]


def lcs_better(A, B):
    costs = [0]
    for c in B:
        for index in range(len(costs) - 1, -1, -1):
            # print(costs, index + 1)
            x_findex_index = A.find(c, costs[index])
            if x_findex_index != -1:
                if index + 1 < len(costs):
                    costs[index + 1] = min(costs[index + 1], x_findex_index + 1)
                else:
                    costs.append(x_findex_index + 1)
    return len(costs) - 1


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    pair_num = int(_input[0])

    word_list = _input[1:]
    # assert len(word_list) == 2 * pair_num
    for k in range(0, len(word_list), 2):
        print(lcs_better(word_list[k].strip(), word_list[k + 1].strip()))

Python: def ser(X, Y):
    dp = [[0] * (len(Y)+1) for x in range(len(X)+1)]
    for i, x in enumerate(X, 1):
        tmp = dp[i]
        pre = dp[i-1]
        for j, y in enumerate(Y, 1):
            if x == y:
                tmp[j] = pre[j-1] + 1
            elif pre[j] < tmp[j-1]:
                tmp[j] = tmp[j-1]
            else:
                tmp[j] = pre[j]
    return(dp[-1][-1])

for _ in range(int(input())):
    X, Y = input(), input()
    print(ser(X, Y))

Python: def find_substr(s,t):
    flag=False
    i=0
    j=0
    n=0
    while i<len(s) and j<len(t):
        if s[i] == t[j]:
            n+=1
            pass
        elif  j < len(t)-1 and s[i] == t[j+1]:
            j+=1
            n+=1
        elif  i < len(s)-1 and s[i+1] == t[j]:
            i+=1
            n+=1
        j+=1
        i+=1

    return n

n = int(input())

for i in range(n):
    s = input()
    t = input()
    print(find_substr(s,t))

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

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")