题解 | #查找两个字符串a,b中的最长公共子串#

s = []
s.append(input())
s.append(input())
if len(s[0]) > len(s[1]):
    s1 = s[1]
    s2 = s[0]
else:
    s1 = s[0]
    s2 = s[1]
dp = [0 for _ in range(len(s1))]
for i in range(len(s1)):
    for j in range(len(s2)):
        if s1[i] == s2[j]:
            l = 0
            x, y = i, j
            while x >= 0 and y >= 0 and s1[x] == s2[y]:
                l += 1
                x -= 1
                y -= 1
            dp[i] = max(dp[i], l)
max_len = 0
max_i = 0
for i in range(len(dp)):
    if dp[i] > max_len:
        max_len = dp[i]
        max_i = i
print(s1[max_i - max_len + 1 : max_i + 1])