Go: package main

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

const max int = 1000 + 1
var A [][]int

func lcs(x, y string) int {
	x = " " + x
	y = " " + y
	for i:=0;i<len(x); i++ {
		for j:=0;j<len(y); j++ {
			A[i][j] = 0
		}
	}
	for i:=1; i<len(x); i++ {
		for j:=1; j<len(y); j++ {
			if x[i] == y[j] {
				A[i][j] = A[i-1][j-1] + 1
			} else if A[i-1][j] > A[i][j-1] {
				A[i][j] = A[i-1][j]
			} else {
				A[i][j] = A[i][j-1]
			}
		}
	}
	return A[len(x)-1][len(y)-1]
}

func nextInt(scanner *bufio.Scanner) int {
	scanner.Scan()
	num, _ := strconv.Atoi(scanner.Text())
	return num 
}

func nextStr(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}


func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	A = make([][]int, max)
	for i := range A {
		A[i] = make([]int, max)
	}
	n := nextInt(scanner)
	for i:=0; i<n; i++ {
		x := nextStr(scanner)
		y := nextStr(scanner)
		fmt.Printf("%d\n", lcs(x, y))
	}
}

Python: for _ in range(int(input())):
    a = input()
    b = input()
    if len(a) < len(b):
        a, b = b, a
    indices = []
    for cb in b:
        bgn_idx = 0
        for i, cur_idx in enumerate(indices):
            chr_idx = a.find(cb, bgn_idx) + 1
            if not chr_idx:
                break
            if chr_idx < cur_idx:
                indices[i] = chr_idx
            bgn_idx = cur_idx
        else:
            chr_idx = a.find(cb, bgn_idx) + 1
            if chr_idx:
                indices.append(chr_idx)
    print(len(indices))

Python: def find_substr(s,t):
    flag=False
    i=0
    j=0
    n=0
    while i<len(s) and j<len(t):
        if s[i] == t[j]:
            i+=1
            j+=1
            n+=1
            continue
        elif  j < len(t)-1 and s[i] == t[j+1]:
            j+=2
            i+=1
            n+=1
        elif  i < len(s)-1 and s[i+1] == t[j]:
            i+=2
            j+=1
            n+=1
        else:
            i+=1
            j+=1
    return n

n = int(input())
for i in range(n):
    s = input()
    t = input()
    print(find_substr(s,t))

Python: def solve(X, Y):
    X = list(X)
    Y = list(Y)
    dp = [[0 for j in range(len(Y)+1)] for i in range(len(X)+1)]
    for i in range(1,len(X)+1):
        for j in range(1,len(Y)+1):
            targetX = X[i-1]
            targetY = Y[j-1]
            if targetX == targetY:
                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(X)][len(Y)]

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

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_recursive(A, B, m, n):
    if m == 0 or n == 0:
        return 0
    elif A[m - 1] == B[n - 1]:
        return 1 + lcs_recursive(A, B, m - 1, n - 1)
    else:
        return max(lcs_recursive(A, B, m, n - 1), lcs_recursive(A, B, m - 1, n))


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()))

    for pair in zip(word_list[::2], word_list[1::2]):
        w1, w2 = map(lambda x: x.strip(), pair)
        l1, l2 = len(w1), len(w2)
        print(w1, w2, l1, l2)
        print(lcs_recursive(w1, w2, l1, l2))

Python: e=input
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]
 print(len(z))

Python: def calc(x,y):
    n = len(x)
    m = len(y)
    d = [[0 for _ in range(m+1)] for _ in range(n+1)]
    for i in range(n):
        s = x[i]
        for j in range(m):
            if s == y[j]:
                d[i+1][j+1] = d[i][j]+1
            else:
                d[i+1][j+1] = max(d[i+1][j],d[i][j+1])
    return d[n][m]

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

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


def search(x, y):
    x_length = len(x)
    y_length = len(y)
    memo = [[0] * (y_length + 1) for i in range(x_length + 1)]
    for i, ch_x in enumerate(x, 1):
        row = memo[i]
        pre_row = memo[i-1]
        for j, ch_y in enumerate(y, 1):
            if ch_x == ch_y:
                row[j] = pre_row[j-1] + 1
            elif pre_row[j] < row[j-1]:
                row[j] = row[j-1]
            else:
                row[j] = pre_row[j]
    return memo[-1][-1]


if __name__ == "__main__":
    n = int(input())
    strs = [list(val) for val in sys.stdin.read().splitlines()]
    result = [search(strs[i*2], strs[i*2+1]) for i in range(n)]
    print(*result, sep="\n")

Python: MAX = 1005
n = int(input())
dp = [[0 for j in range(MAX)] for i in range(MAX)]
X = Y = ""
len_X = len_X = 0
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])
            if X[i] == Y[j]:
                dp[i + 1][j + 1] = dp[i][j] + 1
            else:
                dp[i + 1][j + 1] = max(dp[i][j + 1], dp[i + 1][j])
    print(dp[len_X][len_Y])

Python: q = int(input())
alphabet =[chr(ord('a') + i) for i in range(26)]

for _ in range (q):
    S1 = list(input())
    S2 = list(input())
    S1.sort()
    S2.sort()
    count = 0
    for i in alphabet:
        temp = min(S1.count(i),S2.count(i))
        if temp !=0:
            count +=temp
    print(count)

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


if __name__ == '__main__':

    
    def lcs(X, Y):
        m = len(X)
        n = len(Y)
        c = [[-1 for i in range(n+1)] for j in range(m+1)]
        X = " " + X
        Y = " " + Y
        for i in range(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] == Y[j]:
                    c[i][j] = c[i-1][j-1] + 1
                else:
                    c[i][j] = max(c[i-1][j], c[i][j-1])
        
        return c[m][n]

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

Python: n=int(input())

for i in range(n):
    a=list(input())
    b=list(input())

    r=[[0 for j in range(len(b)+1)]for i in range(len(a)+1)]

    for j in range(1,len(a)+1):
        for k in range(1,len(b)+1):
            c=max(r[j-1][k-1],r[j-1][k],r[j][k-1])
            if a[j-1]==b[k-1]:
                c=max(r[j-1][k-1]+1,r[j-1][k],r[j][k-1])
            
            r[j][k]=c
            print(r[j][k],end="")
        print(" ",end="\n")
    
    print(r[len(a)][len(b)])

Python: n=int(input())

for i in range(n):
    a=list(input())
    b=list(input())
    x=len(a)+1
    y=len(b)+1

    r=[[0 for j in range(y)]for i in range(x)]

    for j in range(1,x):
        for k in range(1,y):
            if r[j-1][k]>r[j][k-1]:
                c=r[j-1][k]
            else:
                c=r[j][k-1]
            if a[j-1]==b[k-1]:
                if r[j-1][k-1]+1>c:
                    c=r[j-1][k-1]+1
            
            r[j][k]=c    
    print(r[x-1][y-1])