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] = dp[i-1][j-1]+1
				} else if S[i-1] != T[j-1] && dp[i-1][j] > dp[i][j-1] {
					dp[i][j] = dp[i-1][j]
				} else {
					dp[i][j] = dp[i][j-1]
				}
				// 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 lcs(X, Y):
    m, n = len(X), len(Y)
    memo = [[0 for _ in range(n + 1)] for _ 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]:
                memo[i][j] = memo[i - 1][j - 1] + 1
            else:
                memo[i][j] = max(memo[i][j - 1], memo[i - 1][j])
    return memo[m][n]

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

Python: def lcs(s1, s2):
    dp = []
    for s2_k in s2:
        bgn_idx = 0
        for i, cur_idx in enumerate(dp):
            chr_idx = s1.find(s2_k, bgn_idx) + 1
            if not chr_idx:
                break
            dp[i] = min(cur_idx, chr_idx)
            bgn_idx = cur_idx
        else:
            chr_idx = s1.find(s2_k, bgn_idx) + 1
            if chr_idx:
                dp.append(chr_idx)
    return len(dp)


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

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)]
        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: q = int(input())

for _ in range(q):
    X, Y = input(), input()
    n_X, n_Y = len(X), len(Y)

    dp = [[0 for _ in range(n_Y + 1)] for _ in range(n_X + 1)]
    for i in range(n_X):
        X_i = X[i]
        dp_i = dp[i]
        dp_i1 = dp[i + 1]
        for j in range(n_Y):
            if X_i == Y[j]:
                x = 1
            else:
                x = 0
            dp_i1[j + 1] = max(dp_i[j] + x, dp_i1[j], dp_i[j + 1])
    print(dp[n_X][n_Y])

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

????????±?????¨??????
"""
import sys
from sys import stdin
input = stdin.readline



def calc_lcs4(X, Y):
    X = ' ' + X
    Y = ' ' + Y
    m = len(X)
    n = len(Y)

    C = [[0]*(n+1) for _ in range(m+1)] #  ???????????§??¨???

    max_lcs = 0

    pre_row = C[0]
    for i in range(1, m):
        row = C[i]
        XX = X[i]
        for j, YY in enumerate(Y):
            if XX == YY:
                pr_j1 = pre_row[j - 1]
                row[j] = pr_j1 + 1
                if pr_j1+1 > max_lcs:
                   max_lcs = pr_j1 + 1
            else:
                pr_j = pre_row[j]
                r_j1 = row[j-1]
                if pr_j >= r_j1:
                    row[j] = pr_j
                else:
                    row[j] = r_j1
        pre_row = row

    print(max_lcs)


if __name__ == '__main__':
    num = int(input())

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

        result = calc_lcs4(X, Y)

Python: def solve(X, Y):
    dp = [[0] * (len(Y)+1)]
    for i in range(1,len(X)+1):
        dp.append([0])
        for j in range(1,len(Y)+1):
            if X[i-1] == Y[j-1]:
                dp[i].append(dp[i-1][j-1] + 1)
            else:
                dp[i].append(max(dp[i-1][j], dp[i][j-1]))
    return dp[len(X)][len(Y)]

num = int(input())
for i in range(num):
    X = input()
    Y = input()
    print(solve(X,Y))

Python: e=input
a=[]
for _ in[0]*int(e()):
 X,z=e(),[]
 for y in e():
  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]
 a+=[len(z)]
print(*a,sep='\n')

Python: def lcs(x, y):
    a = len(x)
    b = len(y)
    c1 = [0] * (b + 1)
    for i in range(a):
        e1 = x[i]
        c2 = c1[:]
        for j in range(b):
            if e1 == y[j]:
                c1[j+1] = c2[j] + 1
            elif c1[j+1] < c1[j]:
                c1[j+1] = c1[j]
    return c1[-1]
    
n = int(input().rstrip())
ret = []
for i in range(n):
    s1 = input().rstrip()
    s2 = input().rstrip()
    ret.append(lcs(s1, s2))
print(*ret, sep="\n")

Python: # -*- coding: utf-8 -*-
"""
Created on Fri May  4 20:33:37 2018
ALDS1_10_C Using Numpy
@author: maezawa
"""

import numpy as np

def longest(x, y):
    m = len(x)
    n = len(y)
    maxl = 0
    c = np.zeros((m+1, n+1), dtype=int)
    for i in range(m):
        for j in range(n):
            #print(i,j)
            if x[i] == y[j]:
                c[i, j] = c[i-1, j-1] + 1
            else:
                c[i, j] = max(c[i-1, j], c[i, j-1])
            maxl = max(maxl, c[i, j])
    return maxl

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

Python: n = int(input())
dataset = []
for i in range(n):
    tmp = []
    tmp.append(input())
    tmp.append(input())
    dataset.append(tmp)
 
for data in dataset:
    m = len(data[0])
    n = len(data[1])
    dp = []
    for x in range(n+1):
        dp.append([0] *(m+1))
 
    for j in range(n):
        for i in range(m):
            if data[0][i] == data[1][j]:
                dp[j+1][i+1] = dp[j][i] + 1
            else:
                #dp[j+1][i+1] = max(dp[j+1][i], dp[j][i+1])
                dp[j+1][i+1] = dp[j+1][i] if dp[j+1][i]>dp[j][i+1] else dp[j][i+1]
    print(dp[n][m])