题解 | #查找两个字符串a,b中的最长公共子串#
查找两个字符串a,b中的最长公共子串
https://www.nowcoder.com/practice/181a1a71c7574266ad07f9739f791506
import sys
S1 = input()
S2 = input()
if len(S1) > len(S2): #让S1是小的，去S2中查找
S1, S2 = S2, S1
max_len = 1
res = ''
for i in range(len(S1)):
for j in range(i+1,len(S1)+1):
if S1[i:j] in S2:
if max_len < j-i:
max_len = j - i
res = S1[i:j]
print(res)