Go: package main

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

var (
	nstr   func() string
	stdout *bufio.Writer
)

func init() {
	nstr = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func main() {
	defer stdout.Flush()

	n := nint()
	xList := make([]string, n)
	yList := make([]string, n)

	for i:=0;i<n ;i++  {
		xList[i] = nstr()
		yList[i] = nstr()
	}

	for i := 0; i<n	; i++  {
		fmt.Println(lcs(xList[i], yList[i]))
	}

}

func lcs(x string, y string) int{
	var m = len(x)
	var n = len(y)

	c := make([][]int, m+1)
	for i:= range c{
		c[i] = make([]int, n+1)
	}
	for i:=	1;i<=m ;i++  {
		for j:=1;j<=n ;j++  {
			if x[i-1] == y[j-1]{
				c[i][j] = c[i-1][j-1] + 1
			}else{
				c[i][j] = int(math.Max(float64(c[i-1][j]), float64(c[i][j-1])))
			}


		}
	}
	return c[m][n]

}


func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+11))
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

func nint64() int64 {
	i, err := strconv.ParseInt(nstr(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func nint() int {
	return int(nint64())
}

func getIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = nint()
	}
	return b
}

func getStringSlice(n int) []string {
	b := make([]string, n)
	for i := 0; i < n; i++ {
		b[i] = nstr()
	}
	return b
}

func gcd(x, y int) int {
	if y == 0 {
		return x
	}
	return gcd(y, x%y)
}

func lcm(x, y int) int {
	return x * y / gcd(x, y)
}

func contains(s []int, e int) bool {
	for _, a := range s {
		if a == e {
			return true
		}
	}
	return false
}

func bin(i int, prefix bool) string {
	i64 := int64(i)

	if prefix {
		return "0b" + strconv.FormatInt(i64, 2)
	} else {
		return strconv.FormatInt(i64, 2)
	}
}

func strReverse(s string) string {
	runes := []rune(s)
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}

	return string(runes)
}

Python: def num_substr(s, t):
    sl = len(s)
    tl = len(t)
    dp = {}
    for i in range(sl + 1):
        dp[i] = {0: 0}
    for j in range(sl + 1):
        dp[0][j] = 0
     
    for i in range(1,sl+1):
        si_1 = s[i-1]
        dpi = dp[i]
        dpi_1 = dp[i-1]
        for j in range(1,tl+1):
            d=1 if si_1 == t[j-1] and dpi_1[j-1] == dpi[j-1] else 0
            dp[i][j] = max(dpi_1[j] ,
                           dpi[j-1] +d)
    return dp[len(s)][len(t)]
 
n = int(input())
for i in range(n):
    s = input()
    t = input()
    print(num_substr(s,t))

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())
    # X = 'abcbdab'
    # Y = 'bdcaba'

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

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

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

Python: def lcs(s, t):
  slen = len(s)
  tlen = len(t)
  dp = [0] * (slen + 1)
  dp[0] = [0] * (tlen + 1)

  for i in range(1, slen + 1):
    dp_prev = dp[i-1]
    dp_cur  = [0] * (tlen + 1)
    c = s[i-1]
    for j in range(1, tlen + 1):
      if c == t[j-1]:
        dp_cur[j] = dp_prev[j-1] + 1
      else:
        dp_cur[j] = max(dp_cur[j-1], dp_prev[j])
    dp[i] = dp_cur

  return dp[slen][tlen]

n = int(raw_input())

for i in range(n):
  x = raw_input()
  y = raw_input()
  print(lcs(x, y))

Python: def lcs(X,Y):
    Xlength = len(X)
    Ylength = len(Y)

    for i in range(Xlength+1):
        c[i][0] = 0
    for i in range(Ylength+1):
        c[0][i] = 0

    for i in range(Xlength):
        for j in range(Ylength):
            if X[i] == Y[j]:
                c[i+1][j+1] = c[i][j]+1
            else:
                c[i+1][j+1] = max(c[i][j+1],c[i+1][j])

    return c[Xlength][Ylength]

    # print(X,Y)
    # if Xlength == 0 or Ylength == 0:
    #     c[Xlength][Ylength] = 0
    #     return c[Xlength][Ylength]
    #
    #
    #
    # if X[Xlength -1] == Y[Ylength -1]:
    #     if c[Xlength-1][Ylength-1] is not None:
    #         c[Xlength][Ylength] = c[Xlength-1][Ylength-1]+1
    #     else:
    #         c[Xlength][Ylength] = lcs(X[:Xlength-1], Y[:Ylength-1])+1
    # else:
    #     if c[Xlength-1][Ylength] is not None and c[Xlength][Ylength-1] is not None:
    #         c[Xlength][Ylength] = max(c[Xlength][Ylength-1],c[Xlength-1][Ylength])
    #     elif c[Xlength-1][Ylength] is not None:
    #         c[Xlength][Ylength] = max(lcs(X,Y[:Ylength-1]),c[Xlength-1][Ylength])
    #     elif c[Xlength][Ylength-1] is not None:
    #         c[Xlength][Ylength] = max(c[Xlength][Ylength-1],lcs(X[:Xlength-1],Y))
    #     else:
    #         c[Xlength][Ylength] = max(lcs(X,Y[:Ylength-1]),lcs(X[:Xlength-1],Y))
    #
    # return c[Xlength][Ylength]


n = int(input())
X = []
Y = []
c = [[None]*1001 for i in range(1001)]


for i in range(n):
    X.append(input())
    Y.append(input())

for i in range(n):
    # print(i)
    print(lcs(X[i],Y[i]))
    # c = [[None]*1001 for i in range(1001)]

Python: def main():
    num = int(input())
    A = []
    for i in range(num):
        X = input()
        Y = " " + input()
        lx = len(X)
        ly = len(Y)
        T = [0] * ly
        for j in range(lx):
            xj = X[j]
            C = T[:]
            for k in range(1,ly):
                k1 = k-1
                if xj == Y[k]:
                    T[k] = C[k1] + 1
                elif T[k] < T[k1]:
                    T[k] = T[k1]
        print(T[k])
if __name__ == '__main__':
    main()

Python: 
def main():
    n = int(input())
    for i in range(n):
        a = input()
        b = input()
        na=len(a)
        nb=len(b)
        array = [[[0]*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())
t = []
for i in range(q):
    X = input()
    Y = input()
    m = len(X)
    n = len(Y)
    c1 = [0] * (n + 1)
    for i in range(m):
        d = X[i]
        c2 = c1[:]
        for j in range(n):
            if (d == Y[j]):
                c1[j + 1] = c2[j] + 1
            elif (c1[j + 1] < c1[j]):
                c1[j + 1] = c1[j]
    print(c1[-1])

Python: # -*- coding: utf-8 -*-
def lcs_sol(x, y):
    n = len(x)
    m = len(y)
    dp = [0 for j in range(m + 1)]

    for i in range(1, n + 1):
        dp_prev = dp[:]
        for j in range(1, m + 1):
            if x[i - 1] == y[j - 1]:
                dp[j] = dp_prev[j - 1] + 1
            elif dp_prev[j] < dp[j - 1]:
                dp[j] = dp[j - 1]

    return dp[m]


if __name__ == '__main__':
    import sys
    q = int(sys.stdin.readline().strip())
    for i in range(q):
        x = sys.stdin.readline().strip()
        y = sys.stdin.readline().strip()
        print(lcs_sol(x, y))