最长回文串manacher算法模板

#include <iostream>#include <string>using namespace std;string preProvess(string s){int n = s.size();if (n == 0)return "^$";string ret = "^";for (int i = 0; i < n; ++i)ret += "#" + s.substr(i, 1);ret += "#$";return ret;}int longgest_palindrome(string s){string T = preProvess(s);int n = T.size();int* p = new int[n];int C = 0, R = 0;for (int i = 1; i < n - 1; ++i){int i_mirror = 2 * C - i;p[i] = (R > i) ? min(R - i, p[i_mirror]) : 0;while (T[i + 1 + p[i]] == T[i - 1 - p[i]])p[i]++;if (i + p[i] > R){C = i;R = i + p[i];}}int max_len = 0;int centerIndex = 0;for (int i = 1; i < n - 1; ++i){if (p[i] > max_len){max_len = p[i];centerIndex = i;}}delete[] p;return max_len;}int main(){string tmp;cin >> tmp;cout << longgest_palindrome(tmp) << endl;return 0;}