KMP求前缀和后缀 #include <iostream> #include <cstring> #include <vector> using namespace std; int main() { string s; cin >> s; string t(s.rbegin(), s.rend()); int n = s.size(); vector<int> ne(n * 2 + 2); s = ' ' + t + '*' + s; for (int i = 2, j = 0; ...