找出a、b的最长公共子串

Question

a  =  input()
b  =  input()
la  =  len(a)
lb  =  len(b)
#建立二维列表，行数la+1，列数lb+1,初值为0
res  =  
lc  =  []
mmax  =  0
for  i  in  range(1,  la+1):
      for  j  in  range(1,  lb+1):
            if  a[i-1]  ==  b[j-1]:
                  res[i][j]  =  res[i-1][j-1]  +  1
                  if():
                        mmax  =  res[i][j]
                        
print(mmax)

可以帮我补一下res后面和if后面的内容吗，因为一直打出来是错的

Answer 1

a = input()
b = input()
la = len(a)
lb = len(b)
#建立二维列表，行数la+1，列数lb+1,初值为0
res = [[0 for i in range(lb+1)] for j in range(la+1)]
lc = []
mmax = 0
for i in range(1, la+1):
    for j in range(1, lb+1):
        if a[i-1] == b[j-1]:
            res[i][j] = res[i-1][j-1] + 1
            if(res[i][j] > mmax):
                mmax = res[i][j]

print(mmax)