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: n=int(input())
al=[]
bl=[]
for i in range(n):
	al.append(list(input()))
	bl.append(list(input()))

for i in range(n):
	a=al.pop(0)
	b=bl.pop(0)
	dp=[[0 for i in range(len(b))] for j in range(len(a))]

	for i in range(len(a)):
		for j in range(len(b)):
			if i==0:
				if j==0:
					if a[i]==b[j]:
						dp[i][j]=1
					else:
						dp[i][j]=0
				elif a[i]==b[j]:
					dp[i][j]=1
				else:
					dp[i][j]=dp[i][j-1]
			elif j==0:
				if a[i]==b[j]:
					dp[i][j]=1
				else:
					dp[i][j]=dp[i-1][j]

			elif a[i]!=b[j]:
				dp[i][j]=max(dp[i-1][j-1],dp[i-1][j],dp[i][j-1])
			else:
				dp[i][j]=dp[i-1][j-1]+1

	print(dp[len(a)-1][len(b)-1])

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()
    s2 = input()
    ret.append(lcs(s1, s2))
print(*ret, sep = '\n')

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

????????±?????¨??????
"""
# 4/5??§Time Limit Exceeded 5.52s ????????????5s??\???????????????????????????

c = []
def prep_array(X, Y):
    """ ??????0???2?¬???????????????¨??????????????????????????\????????????????????§??????????????????????¨?(1000+1)??\???????????? """
    c = [[0]*1001 for _ in range(1001)]
    return c


def check_max(array):
    """ 2?¬????????????????????????§??????????????? """
    max_lcs = 0
    for row in array:
        temp_max = max(row)
        if temp_max > max_lcs:
            max_lcs = temp_max
    return max_lcs


def calc_lcs4(X, Y, c):
    """
    Y[j]?????¢???????????????????????´
    4/5 ?????????????????????????????¨????????????????????????????????°??§6.0?§?
    """
    X = ' ' + X
    Y = ' ' + Y
    m = len(X)
    n = len(Y)
    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]
                cv = pr_j1 + 1
                row[j] = cv
                if cv > max_lcs:
                    max_lcs = cv
            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
    return max_lcs



def calc_lcs3(X, Y, c):
    """
    X[i]???for j?????????????????????????????°????????????????????§???
    4/5 ?????????????????????????????¨????????????????????????????????°??§7.1?§?
    """
    m = len(X)
    n = len(Y)
    X = ' ' + X
    Y = ' ' + Y

    pre_row = c[0]
    for i in range(1, m+1):
        row = c[i]
        XX = X[i]
        for j in range(1, n+1):
            if XX == Y[j]:
                row[j] = pre_row[j - 1] + 1
            elif pre_row[j] >= row[j - 1]:
                row[j] = pre_row[j]
            else:
                row[j] = row[j - 1]
        pre_row = row
    return check_max(c)



def calc_lcs2(X, Y, c):
    """
    c[i][j]????????¢????????????????????????????????§?????????????????¨?????????????????°??????????????????????????£??????????????§???
    4/5 ?????????????????????????????¨????????????????????????????????°??§8.2?§?
    """
    m = len(X)
    n = len(Y)
    X = ' ' + X
    Y = ' ' + Y

    pre_row = c[0]
    for i in range(1, m+1):
        row = c[i]
        for j in range(1, n+1):
            if X[i] == Y[j]:
                row[j] = pre_row[j - 1] + 1
            elif pre_row[j] >= row[j - 1]:
                row[j] = pre_row[j]
            else:
                row[j] = row[j - 1]
        pre_row = row
    return check_max(c)


def calc_lcs1(X, Y):
    """
    array?????????????????¨???byte???????????¨????????¨????§??????????????????????????????????????????§?????¨???????????£?????????int???????????¨???
    4/5 ?????????????????????????????¨????????????????????????????????°??§19.3?§?
    """
    from array import array
    m = len(X)
    n = len(Y)
    X = ' ' + X
    Y = ' ' + Y
    c = array('i', [0] * (1024 * 1024))
    for i in range(1, m+1):
        for j in range(1, n+1):
            if X[i] == Y[j]:
                c[i*1024 + j] = c[(i-1)*1024 + j - 1] + 1
            elif c[(i-1)*1024 + j] >= c[i*1024 + j - 1]:
                c[i*1024 + j] = c[(i-1)*1024 + j]
            else:
                c[i*1024 + j] = c[i*1024 + j - 1]
    return max(c)


def calc_lcs(X, Y, c):
    """
    ??????????????¢?????´????????????????????????????£?????????????
    4/5 ?????????????????????????????¨????????????????????????????????°??§12.5?§?
    """
    m = len(X)
    n = len(Y)
    X = ' ' + X
    Y = ' ' + Y

    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]
    return check_max(c)


if __name__ == '__main__':
    # ??????????????\???
    num = int(input())
    # f = open('input.txt')
    # num = int(f.readline())

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

        # ???????????????
        result = calc_lcs4(X, Y, prep_array(X, Y))
        # result = calc_lcs5(X, Y)

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

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):
            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[x-1][y-1])