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Update include.hh

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Ariel 2024-01-18 12:36:04 +08:00 committed by GitHub
parent 490360c54e
commit d2207f6446
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1 changed files with 18 additions and 20 deletions
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include.hh
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@ -97,17 +97,17 @@ template<typename T, typename... U> void __read(T& x, U&... args) { cin >> x; __
#define popfront(q, ...) __AS_PROCEDURE(auto [__VA_ARGS__] = q.front();q.pop_front();)
/* algorithms */
vector<int> calc_next(string t) { // pi function of t
int m = t.length();
vector<int> next; next.push_back(-1);
int j = -1, i = 0;
while (i < m)
if (j == -1 || t[i] == t[j]) {
++i, ++j;
if (i != m && t[i] == t[j]) next.push_back(next[j]);
else next.push_back(j);
} else j = next[j];
return next;
int n = (int)t.length();
vector<int> pi(n);
for (int i = 1; i < n; i++) {
int j = pi[i - 1];
while (j > 0 && t[i] != t[j]) j = pi[j - 1];
if (t[i] == t[j]) j++;
pi[i] = j;
}
return pi;
}
vector<int> calc_z(string t) { // z function of t
int m = t.length();
@ -127,15 +127,13 @@ vector<int> calc_z(string t) { // z function of t
return z;
}
vector<int> kmp(string s, string t) { // find all t in s
int n = s.length(), m = t.length();
vector<int> next= calc_next(t);
vector<int> res;
int i = 0, j = 0;
while (i < n && j < m)
if (j == -1 || s[i] == t[j]) {
++i, ++j;
if (j == m) res.push_back(i - j), j = next[j];
} else j = next[j];
return res;
string cur = t + '#' + s;
int sz1 = s.size(), sz2 = t.size();
vector<int> v;
vector<int> lps = calc_next(cur);
for (int i = sz2 + 1; i <= sz1 + sz2; i++) {
if (lps[i] == sz2) v.push_back(i - 2 * sz2);
}
return v;
}
/////////////////////////////////////////////////////////