给定一个字符串数组arr[] ,其中包含字符模式,“*”表示任何字符集,包括空字符串。任务是找到一个匹配数组中所有模式的字符串。
注意:如果没有这种可能的模式,则打印 -1。
例子:
Input: arr[] = {“pq*du*q”, “pq*abc*q”, “p*d*q”}
Output: pqduabcdq
Explanation:
Pattern “pqduabcdq” matches all the strings:
String 1:
First “*” can be replaced by a empty string.
Second “*” can be replaced by “abcdq”.
String 2:
First “*” can be replaced by “du”
Second “*” can be replaced by “d”
String 3:
First “*” can be replaced by “q”
Second “*” can be replaced by “uabcd”
Input: arr[] = {“a*c”, “*”}
Output: ac
方法:思路是在所有模式中找到共同的前缀和后缀字符串,然后每个模式的中间可以替换为每个模式中的第一个或最后一个“*”。下面是该方法的说明:
- 创建三个与每个模式的前缀、后缀和中间部分匹配的空字符串。
- 迭代数组中的每个模式,对于每个模式:
- 找到模式中的第一个和最后一个“*”。
- 迭代现有前缀并检查它是否与模式的当前前缀匹配,如果任何字符与模式不匹配,则返回 -1。
- 如果当前模式的前缀中有剩余部分,则将其附加到公共字符串的前缀。
- 同样,匹配模式的后缀。
- 最后,在普通字符串的中间初始化字符串附加字符串的所有中间字符,除了“*”。
- 最后,串联共同字符串,它是前缀,中间和字符串的后缀部分的部分。
下面是上述方法的实现:
C++
// C++ implementation to find the
// string which matches
// all the patterns
#include
using namespace std;
// Function to find a common string
// which matches all the pattern
string find(vector S,int N)
{
// For storing prefix till
// first most * without conflicts
string pref;
// For storing suffix till
// last most * without conflicts
string suff;
// For storing all middle
// characters between
// first and last *
string mid;
// Loop to iterate over every
// pattern of the array
for (int i = 0; i < N; i++) {
// Index of the first "*"
int first = int(
S[i].find_first_of('*')
);
// Index of Last "*"
int last = int(
S[i].find_last_of('*')
);
// Iterate over the first "*"
for (int z = 0; z < int(pref.size()) &&
z < first; z++) {
if (pref[z] != S[i][z]) {
return "*";
}
}
// Prefix till first most *
// without conflicts
for (int z = int(pref.size());
z < first; z++) {
pref += S[i][z];
}
// Iterate till last
// most * from last
for (int z = 0; z < int(suff.size()) &&
int(S[i].size())-1-z > last; z++) {
if (suff[z] != S[i][int(S[i].size())-1-z]) {
return "*";
}
}
// Make suffix till last
// most * without conflicts
for (int z = int(suff.size());
int(S[i].size())-1-z > last; z++) {
suff += S[i][int(S[i].size())-1-z];
}
// Take all middle characters
// in between first and last most *
for (int z = first; z <= last; z++) {
if (S[i][z] != '*') mid += S[i][z];
}
}
reverse(suff.begin(), suff.end());
return pref + mid + suff;
}
// Driver Code
int main() {
int N = 3;
vector s(N);
// Take all
// the strings
s[0]="pq*du*q";
s[1]="pq*abc*q";
s[2]="p*d*q";
// Method for finding
// common string
cout<
Python3
# Python3 implementation
# to find the string which
# matches all the patterns
# Function to find a common
# string which matches all
# the pattern
def find(S, N):
# For storing prefix
# till first most *
# without conflicts
pref = ""
# For storing suffix
# till last most *
# without conflicts
suff = ""
# For storing all middle
# characters between
# first and last *
mid = ""
# Loop to iterate over every
# pattern of the array
for i in range(N):
# Index of the first "*"
first = int(S[i].index("*"))
# Index of Last "*"
last = int(S[i].rindex("*"))
# Iterate over the first "*"
for z in range(len(pref)):
if(z < first):
if(pref[z] != S[i][z]):
return "*"
# Prefix till first most *
# without conflicts
for z in range(len(pref),first):
pref += S[i][z];
# Iterate till last
# most * from last
for z in range(len(suff)):
if(len(S[i]) - 1 - z > last):
if(suff[z] != S[i][len(S[i]) - 1 - z]):
return "*"
# Make suffix till last
# most * without conflicts
for z in range(len(suff),
len(S[i]) - 1 - last):
suff += S[i][len(S[i]) - 1 - z]
# Take all middle characters
# in between first and last most *
for z in range(first, last + 1):
if(S[i][z] != '*'):
mid += S[i][z]
suff=suff[:: -1]
return pref + mid + suff
# Driver Code
N = 3
s = ["" for i in range(N)]
# Take all
# the strings
s[0] = "pq*du*q"
s[1] = "pq*abc*q"
s[2] = "p*d*q"
# Method for finding
# common string
print(find(s, N))
# This code is contributed by avanitrachhadiya2155
输出:
pqduabcdq
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