1910. Remove All Occurrences of a Substring
Given two strings s and part, perform the following operation on s until all occurrences of the substring part are removed:
- Find the leftmost occurrence of the substring part and remove it from s.
Return s after removing all occurrences of part.
A substring is a contiguous sequence of characters in a string.
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| class Solution {
vector<int> getPi(string& s) {
vector<int> pi(s.length(), 0);
for(int i = 1, j = 0; i < s.length(); i++) {
while(j>0 and s[i] != s[j]) {
j = pi[j-1];
}
if(s[i] == s[j])
pi[i] = ++j;
}
return pi;
}
string kmp(string& s, string &p) {
vector<int> pi = getPi(p);
vector<int> index;
string res = "";
for(int i = 0, j = 0; i < s.length(); i++) {
res.push_back(s[i]);
while(j and res.back() != p[j]) j = pi[j-1];
if(res.back() == p[j]) {
index.push_back(++j);
if(j == p.length()) {
for(int j = 0; j < p.length(); j++) {
res.pop_back();
index.pop_back();
}
j = index.size() ? index.back() : 0;
}
} else index.push_back(j);
}
return res;
}
public:
string removeOccurrences(string s, string part) {
return kmp(s,part);
}
};
|
