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 main():
    n = int(input())
    for i in range(n):
        a = input()
        b = input()
        na=len(a)
        nb=len(b)
        array = [[0 for i in range(nb)] for j in range(na)]
        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: #!/usr/bin/python3
import itertools
# main
q = int(input())
for a in range(q):
    X = input()
    Y = input()
    cost = [0]
    for c in Y:
        for i in range(len(cost) - 1, -1, -1):
            index = X.find(c, cost[i]) + 1
            if index:
                if i + 1 < len(cost):
                    cost[i + 1] = min(cost[i + 1], index)
                else:
                    cost.append(index)
    print(len(cost) - 1)

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(len_a):
        a_i = a[i]
        table_i = table[i]
        for j in range(len_b):
            if a_i == b[j]:
                table[i+1][j+1] = table_i[j] + 1
            else:
                table[i+1][j+1] = max(table_i[j+1],table[i+1][j])
    print(table[len_a][len_b])

Python: def num_substr(s, t):
    dp = {}
    for i in range(len(s) + 1):
        dp[i] = {0: 0}
    for j in range(len(t) + 1):
        dp[0][j] = 0
     
    for i in range(1,len(s)+1):
        si_1 = s[i-1]
        dpi = dp[i]
        dpi_1 = dp[i-1]
        Flag=False
        for j in range(1,len(t)+1):
            d=1 if s[i-1] == t[j-1] and dpi_1[j-1] == dp[i][j-1] else 0
            dpi[j] = max(dpi_1[j] ,
                           dpi[j-1] +d)
    return dp[len(s)][len(t)]
 
n = int(input())
for i in range(n):
    s = input()
    t = input()
    print(num_substr(s,t))

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

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

Python: # coding: utf-8

def lcs(str1, str2):
    # dp[i][j]: str1のi番目までとstr2のj番目までを使って作れるlcs
    dp = [[0 for _ in range(len(str2)+10)] for _ in range(len(str1)+10)]
    # 計算量は1000*1000=10^6なんだけど時間切れ？
    for i in range(0,len(str1)):
        for j in range(0,len(str2)):
            v = max(dp[i+1][j],dp[i][j+1])
            if str1[i] == str2[j]:
                dp[i+1][j+1] = max(v,dp[i][j] + 1)
            else:
                dp[i+1][j+1] = max(v,dp[i][j])
    return dp[len(str1)][len(str2)]

# てか、普通のdpじゃ通らないってどんだけシビアなんだ
def lcs_another(str1, str2):
    # str1の中の文字列とstr2の中の文字列が一致したらその位置から先を＋１するだけ
    # なんか自然には思い浮かばないなあ
    dp = [0 for _ in range(len(str2)+10)]
    for c1 in str1:
        tmp = dp[:]
        for i, c2 in enumerate(str2):
            if c1 == c2:
                dp[i+1] = tmp[i]+1
            elif dp[i+1] < dp[i]:
                dp[i+1] = dp[i]
    return dp[len(str2)]

p = int(input().rstrip())
for _ in range(p):
    line1 = input().rstrip()
    line2 = input().rstrip()
    print(lcs_another(line1,line2))

Python: MAX = 1005
n = int(input())
dp = [[0 for j in range(MAX)] for i in range(MAX)]
for _ in range(n):
    X = input()
    Y = input()
    len_X = len(X)
    len_Y = len(Y)

    for i in range(len_X):
        for j in range(len_Y):
            dp[i + 1][j + 1] = dp[i][j] + 1 if X[i] == Y[j] else max(dp[i][j + 1], dp[i + 1][j])
    print(dp[len_X][len_Y])

Python: n=int(input())

l=[]

for i in range(n):
	a=al.list(input())
	b=bl.list(input())
	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])

	l.append(dp[len(a)-1][len(b)-1])

for i in l:
	print(l)

Python: # -*- coding: utf-8 -*-
import sys
from itertools import product
sys.setrecursionlimit(100000)

N = int(input())

def calc_LCS(n, m):
    if n == 0 or m == 0:
        return 0
    elif X[n] == Y[m]:
        LCS[n][m] = LCS[n-1][m-1] + 1
        return LCS[n][m]
    else:
        LCS[n][m] = max(LCS[n-1][m], LCS[n][m-1])
        return LCS[n][m]
        

for _ in range(N):
    X = ["  "] + list(input())
    Y = [" "] + list(input())
    LCS = [[0 for _ in range(len(Y))] for _ in range(len(X))]
    max_ = 0
    for n, m in product(range(len(X)), range(len(Y))):        
        if n == 0 or m == 0:
            pass

        elif X[n] == Y[m]:
            LCS[n][m] = LCS[n-1][m-1] + 1
            
            max_ =  max(LCS[n][m], max_)
        else:
            LCS[n][m] = max(LCS[n-1][m], LCS[n][m-1])
            max_ = max(LCS[n][m], max_)
    print(max_)