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(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)

def solve():
    N = int(input())
    for _ in range(N):
        x = input()
        y = input()
        print(lcs(x, y))

if __name__ == '__main__':
    solve()

Python: """
problem statment url: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_10_C
"""

from __future__ import division
from sys import stdin, maxint

def lcs(s1, s2):
	dp = [[0 for _ in range(len(s2) + 1)] for _ 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])

	return dp[len(s1)][len(s2)]

if __name__ == '__main__':
	tc = int(stdin.readline())
	for _ in range(tc):
		sa = stdin.readline().strip()
		sb = stdin.readline().strip()
		print(lcs(sa, sb))

Python: import numpy as np
def f(i,j):
    if i == 0 or j == 0:
        if s1[i] == s2[j]:
            x[i][j] = 1
        else:
            if i == 0:
                x[i][j] = x[i][j-1]
            else:
                x[i][j] = x[i-1][j]
    elif s1[i] == s2[j]:
        x[i][j] = max(x[i-1][j-1]+1,x[i][j-1],x[i-1][j])
    else:
        x[i][j] = max(x[i-1][j-1],x[i][j-1],x[i-1][j])

n = int(input())
for i in range(n):
    s1 = input()
    s2 = input()
    x = np.zeros((len(s1),len(s2)))
    for j in range(len(s1)):
        for k in range(len(s2)):
            f(j,k)
            
    print(x[len(s1)-1][len(s2)-1])
#print(*x)

Python: import sys

n=int(input())

for _ in range(n):
	x=sys.stdin.readline().rstrip('\r\n')
	y=sys.stdin.readline().rstrip('\r\n')
	
	list=[0]
	for z in y:
		for i in range(len(list)-1,-1,-1):
			tmp=x.find(z,list[i])
			if tmp+1:
				if i+1<len(list):
					list[i+1]=min(list[i+1],tmp+1)
				else:
					list.append(tmp+1)
print(len(list)-1)

Python: for _ in range(int(input())):
    x = list(input())
    y = list(input())
    lx = len(x)
    ly = len(y)
    dp = [[0] * (ly + 1) for i in range(lx + 1)]
    for i in range(lx):
        for j in range(ly):
            if x[i] == y[j]:
                dp[i + 1][j + 1] = dp[i][j] + 1
            else:
                dp[i + 1][j + 1] = max(dp[i + 1][j], dp[i][j + 1])
    print(dp[-1][-1])

Python: q = int(input())
for _ in range(q):
    x = input()
    y = input()
    m = len(x)
    n = len(y)
    c = [[0 for _ in range(n + 1)] for _ in range(m + 1)]
    for i in range(1, 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 - 1] == y[j - 1]:
                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]
    print(c[m][n])

Python: def main():
    num = int(input())
    for i in range(num):
        X = " " + input()
        Y = " " + input()
        lx = len(X)
        ly = len(Y)
        T = [0] * ly
        for j in range(1,lx):
            C = T[:]
            for k in range(1,ly):
                k1 = k-1
                if X[j] == Y[k]:
                    T[k] = C[k1] + 1
                elif C[k] < T[k1]:
                    T[k] = T[k1]
        print(T[k])

if __name__ == '__main__':
    main()

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

import random
import sys
import os
import pprint


def LCS(s0, s1):
    m = len(s0)
    n = len(s1)

    # memo[i][j]
    memo = [[0 for j in range(n)] for i in range(m)]

    # fill at index 0
    for i in range(m):
        if s1[0] in s0[0:i+1]:
            memo[i][0] = 1
    for j in range(n):
        if s0[0] in s1[0:j+1]:
            memo[0][j] = 1

    # fill memo
    for i in range(1, m):
        for j in range(1, n):
            # same last
            if s0[i] == s1[j]:
                memo[i][j] = memo[i-1][j-1] + 1
            else:
                memo[i][j] = max(memo[i-1][j], memo[i][j-1])
    return memo[m-1][n-1]

#fd = os.open('ALDS1_10_C.txt', os.O_RDONLY)
#os.dup2(fd, sys.stdin.fileno())

n = int(input())
for _ in range(n):
    s0 = input()
    s1 = input()
    l = LCS(s0, s1)
    print(l)

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
    set_x = set(x)
    c = defaultdict(list)
    for i, s in enumerate(x):
        c[s].append(i)
    li = [0] * len_x
    for s in y:
        for i in c[s][::-1]:
            if i == 0:
                li[i] = 1
            else:
                li[i] = max(li[:i]) + 1
    print(max(li))

Python: n = int(input())
for _ in range(n):
    a, b = input(), input()
    indices = []
    for cb in b:
        bgn_idx = 0
        for i in range(len(indices) + 1):
            chr_idx = a.find(cb, bgn_idx) + 1
            if chr_idx:
                if i < len(indices):
                    bgn_idx = indices[i]
                    if chr_idx < bgn_idx:
                        indices[i] = chr_idx
                else:
                    indices.append(chr_idx)
            else:
                break
    print(len(indices))