Go: package main

import "fmt"

func initialize_grid(width int,height int)[][]int{
	var grid [][]int
	for i:=0;i<height+1;i++{
		var grid_row  []int
		for j:=0;j<width+1;j++{
			grid_row = append(grid_row,0)
		}
		grid = append(grid,grid_row[:])
	}
	return grid
}

func ma(x int,y int)int{
	if x >= y{
		return x
	}else{
		return y
	}
}

func main()  {
	//Take input
	var num int
	var st1,st2 string
	var string_pairs [][]string
	fmt.Scan(&num)
	for i:=0;i<num;i++{
		var string_pair []string
		fmt.Scan(&st1)
		fmt.Scan(&st2)
		string_pair = append(string_pair,st1,st2)
		string_pairs = append(string_pairs,string_pair)
	}
	//DP
	//initialize grid
	for i:=0;i<num;i++{
		string_1 := string_pairs[i][0]
		string_2 := string_pairs[i][1]

		dp := initialize_grid(len(string_2),len(string_1))

		for j:=1;j<len(string_1)+1;j++{
			for k:=1;k<len(string_2)+1;k++{
				if string_1[j-1] == string_2[k-1]{
					dp[j][k] = dp[j-1][k-1] + 1
				}else{
					dp[j][k] = ma(dp[j-1][k],dp[j][k-1])
				}
			}
		}
		fmt.Println(dp[len(string_1)][len(string_2)])
	}
}

Python: import sys
def lcs(X, Y):
    m = len(X)
    n = len(Y)
    # c = [[0 for i in range(n+1)] for i in range(m+1)]
    c = [None]*(m+1)
    for i in range(m+1):
        c[i] = [0]*(n+1)
    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]
    return str(c[m][n])

q = int(input())
for i in range(q):
    X = input()
    Y = input()
    print(lcs(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 = [[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: q = int(input())

l = []
x = ""
y = ""

for i in range(q):
    x = input()
    y = input()
 
    yLen = len(y)
    xLen = len(x)
    l = [[0] * xLen for j in range(yLen)]

    for j in range(yLen):
        for k in range(xLen):
            if k == 0 and j == 0:
                if x[k] == y[j]:
                    l[j][k] = 1
                else:
                    l[j][k] = 0
            elif k == 0:
                if x[k] == y[j]:
                    l[j][k] = 1
                else:
                    l[j][k] = l[j - 1][k]
            elif j == 0:
                if x[k] == y[j]:
                    l[j][k] = 1
                else:
                    l[j][k] = l[j][k - 1]
            elif x[k] == y[j]:
                l[j][k] = 1 + l[j - 1][k - 1]
            else:
                if l[j][k - 1] > l[j - 1][k]:
                    l[j][k] = l[j][k - 1]
                else:
                    l[j][k] = l[j - 1][k]
 
    print(l[yLen- 1][xLen - 1])

Python: n=int(input())
ans=[]
for k in range(n):
    s1=input()
    s2=input()
    dp=[[0 for i in range(len(s2)+1)] for j 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])


    ans.append(dp[len(s1+1)][len(s2+1)])
for a in ans:
    print(a)

Python: q = int(input())

def lcs(X, Y):
    x_len = len(X)
    y_len = len(Y)
    dp = [[0 for _ in range(y_len+1)] for _ in range(x_len+1)]
    
    for i, x in enumerate(X):
        for j, y in enumerate(Y):
            if x == y:
                dp[i][j] = dp[i-1][j-1] + 1
            else:
                dp[i][j] = max(dp[i-1][j], dp[i][j-1])
                               
    return max(max(dp))
    
for _ in range(q):
    X = input()
    Y = input()
    print(lcs(X, Y))

Python: for _ in[0]*int(input()):
 X,Y=' '+input(),' '+input();m,n=len(X),len(Y);c=[[0]*n for _ in[0]*m]
 for i in range(1,m):
  for j in range(1,n):c[i][j]=(max(c[i-1][j],c[i][j-1]),1+c[i-1][j-1])[X[i]==Y[j]]
 print(c[m-1][n-1])

Python: import bisect

INF = float('inf')
q = int(input())
for i in range(q):
    x = input()
    y = input()
    dic = {}
    for i,xx in enumerate(x):
        if xx in dic : dic[xx].append(i)
        else : dic[xx] = [i]
    inc = []
    size = -1
    for j,yy in enumerate(y):
        if not (yy in dic):continue
        inc.append([])
        size += 1
        for k in dic[yy]:
            inc[size].append(k)
    #incのLISを求めればよい
    n = len(inc)
    dp =  [INF for i in range(n)]
    temp = [INF for i in range(n)]

    for ii in inc:
        for i in ii:
            p = bisect.bisect_left(dp, i)
            temp[p] = min(i,temp[p])
        dp = temp[:]


    print(bisect.bisect_left(dp, INF))

Python: ans=[]
n=int(input())
for i in range(n):
    X=input()
    Y=input()
    com=[0]
    for i in Y:
        for j in range(len(com)-1,-1,-1):
            tmp=X.find(i,com[j])
            if tmp+1:
                if j+1<len(com):
                    com[j+1]=min(com[j+1],tmp+1)
                else:
                    com.append(tmp+1) 
    ans.append(len(com)-1)
for i in range(n):
    print(ans[i])

Python: def longest_common(x, y):
    cost = [0]
    for c in y:
        for i in range(len(cost) -1, -1, -1):
            index = x.find(c, cost[i]) + 1
            if index:
                if i + 1 < len(cost):
                    cost[i + 1] = min(cost[i + 1], index)
                else:
                    cost.append(index)
    return len(cost)  - 1
            

n = int(input())
for _ in range(n):
    x = input()
    y = input()
    print(longest_common(x, y))

Python: q=int(input())
for i in range(q):
    s1=input()
    s2=input()
    ls1=len(s1)
    ls2=len(s2)
    f=[[0 for k in range(ls2+1)] for j in range(ls1+1)]
    for j in range(1,ls1+1):
        tmp=s1[j-1]
        for k in range(1,ls2+1):
            if tmp==s2[k-1]:
                f[j][k]=f[j-1][k-1]+1
            else:
                f[j][k]=max(f[j-1][k],f[j][k-1])
    print(f[j][k])

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

for i in range(q):
    X = input()
    Y = input()
    x = len(X)
    y = len(Y)
    dp = [[0] * (y + 1)] * (x + 1)
    ans = 0
    for j in range(1, x+1):
        for k in range(1, y+1):
            X_j = X[:j]
            Y_k = Y[:k]
            if X_j[-1] == Y_k[-1]:
                dp[j][k] = dp[j - 1][k - 1] + 1
            else:
                dp[j][k] = max(dp[j - 1][k],dp[j][k - 1])
            ans = max(ans, dp[j][k])
    print(ans)