Question

这是一个基本问题，但是我在任何地方都找不到正确的答案。我在python中有2个相等长度的字符串，我想查找第二个字符串中是否包含至少n个字符（n可以小于字符串长度的任何数字）（第一个字符串包含相同的顺序）。

例如：

s1 = 'TAGCACTTT'
s2 = 'CGATGATTT'
s3 = 'AGACGGCCT'
n = 6

匹配s1和s2应该返回True，因为s2按顺序包含字母“ AGATTT”，而匹配s1和s3应该返回False，因为只有5个字母匹配。我如何有效地做到这一点？

Answer 1

def max_sub(X, Y, m, n):
    if m == 0 or n == 0:
        return 0;
    elif X[m - 1] == Y[n - 1]:
        return 1 + max_sub(X, Y, m - 1, n - 1);
    else:
        return max(max_sub(X, Y, m, n - 1), max_sub(X, Y, m - 1, n))

s1 = 'TAGCACTTT'
s2 = 'CGATGATTT'
s3 = 'AGACGGCCT'
n = 6

# Permutations using library function
from itertools import permutations

# Get all permutations of [s1,s2,s3]
perm = permutations([s1, s2, s3],2)

# pass over the obtained permutations
for i in list(perm):
    len_ = max_sub(i[0], i[1], len(i[0]), len(i[1]))
    if len_ >= n:
        print("For {},{} length of common substring is: {}, True ".format(i[0], i[1], max_sub(i[0], i[1], len(i[0]), len(i[1]))))
    else:
        print("For {},{} length of common substring is: {}, False ".format(i[0], i[1], max_sub(i[0], i[1], len(i[0]), len(i[1]))))

输出：

For TAGCACTTT,CGATGATTT length of common substring is: 6, True 
For TAGCACTTT,AGACGGCCT length of common substring is: 5, False 
For CGATGATTT,TAGCACTTT length of common substring is: 6, True 
For CGATGATTT,AGACGGCCT length of common substring is: 4, False 
For AGACGGCCT,TAGCACTTT length of common substring is: 5, False 
For AGACGGCCT,CGATGATTT length of common substring is: 4, False

在Python中以相同顺序匹配另一个字符串中的字符串字符

1 个答案: