Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	Q := sc.nextInt()
	for q := 0; q < Q; q++ {
		X, Y := sc.nextStr(), sc.nextStr()
		xLen, yLen := len(X), len(Y)
		dp := make([][]int, xLen+1)
		for i := 0; i <= xLen; i++ {
			dp[i] = make([]int, yLen+1)
		}
		for x := 0; x <= xLen; x++ {
			for y := 0; y <= yLen; y++ {
				if x == 0 || y == 0 {
					dp[x][y] = 0
				} else if X[x-1] == Y[y-1] {
					dp[x][y] = dp[x-1][y-1] + 1
				} else {
					dp[x][y] = max(dp[x-1][y], dp[x][y-1])
				}
			}
		}
		fmt.Fprintln(wtr, dp[xLen][yLen])
	}

	wtr.Flush()
}

Python: # -*- coding: utf-8 -*-


def lcs(X, Y):
    memo = dict()
    for i in range(len(X)+1):
        memo[(i, 0)] = 0
    for j in range(len(Y)+1):
        memo[(0, j)] = 0
    for i, x in enumerate(X):
        for j, y in enumerate(Y):
            if x == y:
                memo[(i+1,j+1)] = memo[i, j] + 1
            else:
                memo[(i+1,j+1)] = max(memo[i, j+1], memo[i+1, j])
    return memo[(len(X), len(Y))]


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

Python: ans=[]
n=int(input("n="))
for i in range(n):
    X=input("X=")
    Y=input("Y=")
    com=[0]
    for i in X:
        for j in range(len(com)-1,-1,-1):
            tmp=X.find(i,com[j])+1
            if tmp:
                if j+1<len(com):
                    com[j+1]=min(com[j+1],tmp)
                else:
                    com.append(tmp)     
    ans.append(len(com)-1)
for i in range(n):
    print(ans[i])

Python: # -*- coding: utf-8 -*-
"""
http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_10_C

????????±?????¨??????
"""
# 3/5??§Time Limit Exceeded 14.27s ????????????5s??\???????????????????????????

def calc_lcs(X, Y):
    from array import array
    max_lcs = 0
    m = len(X)
    n = len(Y)
    X = ' ' + X
    Y = ' ' + Y
    c = array('l', [0] * (1001 * 1001))
    for i in range(1, m+1):
        for j in range(1, n+1):
            if X[i] == Y[j]:
                c[i*1001 + j] = c[(i-1)*1001 + j - 1] + 1
            elif c[(i-1)*1001 + j] >= c[i*1001 + j - 1]:
                c[i*1001 + j] = c[(i-1)*1001 + j]
            else:
                c[i*1001 + j] = c[i*1001 + j - 1]
            max_lcs = max(max_lcs, c[i*1001 + j])
    return max_lcs


if __name__ == '__main__':
    # ??????????????\???
    num = int(input())
    # f = open('input.txt')
    # num = int(f.readline())

    for _ in range(num):
        X = input()
        Y = input()
        # X = f.readline().strip()
        # Y = f.readline().strip()

        # ???????????????
        result = calc_lcs(X, Y)

        # ???????????¨???
        print(result)

Python: import sys
import functools as ft
sys.setrecursionlimit(10000)

q = int(input())
X = ""
Y = ""
memo = [[]]

def print_memo() :
    for x in range(len(X)):
        print(ft.reduce(lambda x,y: x + str(y) + "\t" ,memo[x], ""))

def LCS(x, y):
    if (x < 0) or (y < 0):
        return 0
    elif memo[x][y] != -1:
        return memo[x][y]
    elif X[x] == Y[y]:
        memo[x][y] =  LCS(x-1, y-1) + 1
        return memo[x][y]
    else:
        memo[x][y] = max(LCS(x-1,y), LCS(x,y-1))
        return memo[x][y]


for c in range(q):
    X = input()
    Y = input()
    memo = [[-1 for j in range(len(Y))] for i in range(len(X))]
    print(LCS(len(X)-1, len(Y)-1))
    #print_memo()

Python: def lcs(x, y):
    m, n = len(x), len(y)
    dp = [[0 for j 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]:
                dp[i][j] = dp[i-1][j-1] + 1
            else:
                dp[i][j] = max(dp[i][j-1], dp[i-1][j])

    return dp[m][n]


def main():
    q = int(input())

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


if __name__ == '__main__':
    main()

Python: 
def lcs():
    A = input()
    B = input()

    m = len(A)
    n = len(B)

    dp = [[0 for i in range(n + 1)] for j in range(m + 1)]

    maxl = 0

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

            maxl = max(maxl, dp[i][j])

    return maxl

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

Python: def len_LCS(X,Y):
    D = {}
    def main(X,Y):
        if len(X) == 0: return 0
        if (X,Y) in D: return D[(X,Y)]
        if len(X) == 1:
            D[(X,Y)] = 1 if X[0] in Y else 0
        elif X[0] in Y:
            if Y.index(X[0]) == len(Y)-1:
                D[(X,Y)] = max(1,main(X[1:],Y[:])) 
            else: 
                D[(X,Y)]=  max(main(X[1:],Y[Y.index(X[0])+1:]) + 1,\
                               main(X[1:],Y[:]))
        else:
             D[(X,Y)] = main(X[1:],Y[:]) 
        return D[(X,Y)]
    return main(X,Y)
        
if __name__=='__main__':
    n = int(input())
    for _ in range(n):
        X = input()
        Y = input()
        print(len_LCS(X,Y))

Python: def main():
    num = int(input())
    for i in range(num):
        X = " " + input()
        Y = " " + input()
        lx = len(X)
        ly = len(Y)
        max = 0
        XY = [[0] * ly for i in range(lx)]
        for j in range(1,lx):
            for k in range(1,ly):
                if X[j] == Y[k]:
                    XY[j][k] = XY[j-1][k-1] + 1
                elif XY[j-1][k] > XY[j][k-1]:
                    XY[j][k] = XY[j-1][k]
                else:
                    XY[j][k] = XY[j][k-1]
                if max < XY[j][k]:
                    max = XY[j][k]
        print(max)

if __name__ == '__main__':
    main()

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