Go: package main

import (
	. "fmt"
    "math"
)

// func init() { Println("----------------------------------------") }

func main() {
    const L_MAX = 1003

	var q int
	Scanf("%d", &q)
	X := make([]string, 0, 150)
	Y := make([]string, 0, 150)
	for i := 0; i < 2 * q; i++ {
	    var tmp string
	    Scanf("%s", &tmp)

	    if i % 2 == 0 {
	        X = append(X, tmp)
	    } else {
	        Y = append(Y, tmp)
	    }
	}

    for i := 0; i < q; i++ {
        dp := make([][]int, L_MAX)
        for k, _ := range dp {
            dp[k] = make([]int, L_MAX)
        }

        x, y := X[i], Y[i]

        // init
        isXFound := false
        for c := 0; c < len(x); c++ {
            if isXFound || y[0] == x[c] {
                dp[0][c] = 1
                isXFound = true
            }
        }
        isYFound := false
        for r := 0; r < len(y); r++ {
            if isYFound || x[0] == y[r] {
                dp[r][0] = 1
                isYFound = true
            }
        }

        for r := 1; r < len(y); r++ {
            for c := 1; c < len(x); c++ {
                // dp[r][c]
                if x[c] == y[r] {
                    dp[r][c] = int(math.Max(float64(dp[r - 1][c - 1] + 1), float64(dp[r][c])))
                }

                dp[r][c] = int(math.Max(float64(dp[r][c]), math.Max(float64(dp[r - 1][c]), float64(dp[r][c - 1]))))
            }
        }
        Println(dp[len(y) - 1][len(x) - 1])

        // LCSも求めておく
        // ans := ""
        // r, c := len(y) - 1, len(x) - 1
        // for r >= 0 && c >= 0 {
        //     if y[r] == x[c] {
        //         ans = string(x[c]) + ans
        //         r--
        //         c--
        //     } else {
        //         if dp[r - 1][c] > dp[r][c - 1] {
        //             r--
        //         } else {
        //             c--
        //         }
        //     }
        // }
        // Println(ans)
    }
}

Python: def lcs(str1,str2):
    c=[[0 for _ in range(100000)] for _ in range(100000)]
    m=len(str1)
    n=len(str2)
    maxl=0
    str1=" "+str1
    str2=" "+str2

    i=1
    j=1
    while(i<=m):
        while(j<=n):
            if(str1[i]==str2[j]):
                c[i][j]=c[i-1][j-1]+1
              #  print(c[i][j])
            else:
                c[i][j]=max(c[i-1][j],c[i][j-1])
            maxl=max(maxl,c[i][j])
            j+=1
        i+=1
        j=0

    return maxl

def main():
    n=int(input())
    i=0
    while(i<n):
        str1=str(input())
        str2=str(input())
        print(int(lcs(str1,str2)))
        i+=1

main()

Python: def lcs(x, y):
    a = len(x)
    b = len(y)
    c1 = [0] * (b + 1)
    for i in range(a):
        c2 = c1[:]
        for j in range(b):
            if x[i] == 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 = [0] * n
for i in range(n):
    s1 = input().rstrip()
    s2 = input().rstrip()
    ret[i] = lcs(s1, s2)
for i in range(n):
    print(ret[i])

Python: q = int(input())
for i in range(q):
    x = input()
    y = input()
    co = []

    for j, s in enumerate(x):
        co.append([])
        co[j].append(-1)
        if j == 0:
            end = y.find(s)
            if end != -1:
                co[j].append(end)
        else:
            for k, t in enumerate(co[j-1][:-1]):
                end = y.find(s, t+1)
                if end != -1:
                    co[j].append(min(end, co[j-1][k+1]))
                else:
                    co[j].append(co[j-1][k+1])
            end = y.find(s, co[j-1][-1]+1)

            if end != -1:
                co[j].append(end)

    print(len(co[-1])-1)

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 = tuple([[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
            else:
                count_list[i][j] = max(count_list[i - 1][j], count_list[i][j - 1])

    return count_list[m][n]


def lcs_better(A, B):
    cost_history = [None]
    for ele in B:
        for index in range(len(cost_history) - 1, -1, -1):
            # ???????¬??????°????????????????§???¨A??\?????°??????(ele), ????????°?????????
            found = A.find(ele, cost_history[index])
            if found != -1:
                if index + 1 < len(cost_history):
                    cost_history[index + 1] = min(cost_history[index + 1], found + 1)
                # ??¨???????????°?????¢?????°?????¶?????°????????´???
                else:
                    # assert index + 1 == len(cost_history)
                    cost_history.append(found + 1)

    return len(cost_history) - 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(word_list[k].strip(), word_list[k + 1].strip()))

Python: import sys
def lcs(X, Y):
    x = len(X) + 1
    y = len(Y) + 1
    c = [0 for y in range(y)]

    for i in range(1, x):
        tmp = c[:]
        for j in range(1, y):
            if X[i - 1] == Y[j - 1]:
                c[j] = tmp[j - 1] + 1
            else:
                c[j] = max(tmp[j], c[j - 1])
    return c[y - 1]

n = int(input())

for i in range(n):
    X = sys.stdin.readline()[:-1]
    Y = sys.stdin.readline()[:-1]
    print(lcs(X, Y))

Python: for _ in[0]*int(input()):
 X,z=input(),[]
 for y in input():
  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]
 print(len(z))

Python: def calc_lcs(X, Y):
    max_lcs = 0
    m = len(X)
    n = len(Y)
    X = ' ' + X
    Y = ' ' + Y
    c = [[0]*1001 for i in range(1000+1)]
    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]
            else:
                c[i][j] = c[i][j - 1]
            max_lcs = max(max_lcs, c[i][j])
    return max_lcs


if __name__ == '__main__':
    # ??????????????\???
    num = int(input())

    for _ in range(num):
        X = input()
        Y = input()
        # X = 'abcbdab'
        # Y = 'bdcaba'


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

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

Python: import sys

def lcs(X, Y):
    c = [0 for _ in range(len(Y) + 1)]
    for i in X:
        tmp = c[:]
        for ji, yc in enumerate(Y):
            j = ji + 1
            if i == yc:
                c[j] = tmp[j - 1] + 1
            elif c[j] < c[j - 1]:
                c[j] = c[j - 1]
    return c[-1]

n = int(input())

for i in range(n):
    X = sys.stdin.readline()[:-1]
    Y = sys.stdin.readline()[:-1]
    print(lcs(X, Y))

Python: from collections import defaultdict
q = int(input())
for _ in range(q):
    x = input()
    y = input()
    len_x = len(x)
    len_y = len(y)
    if len_x < len_y:
        len_x, len_y = len_y, len_x
        x, y = y, x
    c = defaultdict(list)
    for i, s in enumerate(x):
        c[s].append(i)
    li = [0] * len_x
    for s in y:
        if s in x:
            for i in c[s][::-1]:
                if i == 0:
                    li[i] = 1
                else:
                    li[i] = max(li[:i]) + 1
    print(max(li))