#include <iostream> #include <string> #include <unordered_map> #include <queue> using namespace std; const int MAX_SIZE = 250 * 1000; bool isPalindrome(string str) { for (unsigned i = 0; i < str.size() / 2; ++i) { if (str[i] != str[str.size() - i - 1]) { return false; } } return true; } bool isPalindromePartial() { unordered_map<char, int> charCount; unordered_map<int, int> doubleCharCount; int len = 0; char prev = 1; string begStr; queue<char> endStr; for(char c = 'a'; cin >> c && c >= 'a'; ++len) { if(prev != 1) doubleCharCount[c * 1000 + prev] += 1; charCount[c] += 1; if (len < MAX_SIZE) { begStr += c; } else { endStr.push(c); if (endStr.size() > MAX_SIZE) endStr.pop(); } prev = c; } // we can do it if (len == begStr.size() + endStr.size()) { while (!endStr.empty()) { begStr += endStr.front(); endStr.pop(); } return isPalindrome(begStr); } // compare endings for (int i = endStr.size() - 1 ; i >= 0 ; --i) { if (begStr[i] != endStr.front()) return false; endStr.pop(); } // parity of letters int oddNum = 0; for (auto pair : charCount) { if (pair.second % 2 == 1) { ++oddNum; if (oddNum > 1) return false; } } if (len % 2 == 1 && oddNum > 0) return false; // parity of pairs of letters oddNum = 0; for (auto pair : doubleCharCount) { int reverse = 1000 * (pair.first % 1000) + pair.first / 1000; if (doubleCharCount.count(reverse) == 0 || doubleCharCount[reverse] != pair.second) { ++oddNum; if (oddNum > 1) return false; } } if (len % 2 == 0 && oddNum > 0) return false; return true; } int main() { ios::sync_with_stdio(false); int N; cin >> N; bool palin; if (N > 0 && N < 2 * MAX_SIZE) { string str; cin >> str; palin = isPalindrome(str); } else { palin = isPalindromePartial(); } if(palin) cout << "TAK" << endl; else cout << "NIE" << endl; return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 | #include <iostream> #include <string> #include <unordered_map> #include <queue> using namespace std; const int MAX_SIZE = 250 * 1000; bool isPalindrome(string str) { for (unsigned i = 0; i < str.size() / 2; ++i) { if (str[i] != str[str.size() - i - 1]) { return false; } } return true; } bool isPalindromePartial() { unordered_map<char, int> charCount; unordered_map<int, int> doubleCharCount; int len = 0; char prev = 1; string begStr; queue<char> endStr; for(char c = 'a'; cin >> c && c >= 'a'; ++len) { if(prev != 1) doubleCharCount[c * 1000 + prev] += 1; charCount[c] += 1; if (len < MAX_SIZE) { begStr += c; } else { endStr.push(c); if (endStr.size() > MAX_SIZE) endStr.pop(); } prev = c; } // we can do it if (len == begStr.size() + endStr.size()) { while (!endStr.empty()) { begStr += endStr.front(); endStr.pop(); } return isPalindrome(begStr); } // compare endings for (int i = endStr.size() - 1 ; i >= 0 ; --i) { if (begStr[i] != endStr.front()) return false; endStr.pop(); } // parity of letters int oddNum = 0; for (auto pair : charCount) { if (pair.second % 2 == 1) { ++oddNum; if (oddNum > 1) return false; } } if (len % 2 == 1 && oddNum > 0) return false; // parity of pairs of letters oddNum = 0; for (auto pair : doubleCharCount) { int reverse = 1000 * (pair.first % 1000) + pair.first / 1000; if (doubleCharCount.count(reverse) == 0 || doubleCharCount[reverse] != pair.second) { ++oddNum; if (oddNum > 1) return false; } } if (len % 2 == 0 && oddNum > 0) return false; return true; } int main() { ios::sync_with_stdio(false); int N; cin >> N; bool palin; if (N > 0 && N < 2 * MAX_SIZE) { string str; cin >> str; palin = isPalindrome(str); } else { palin = isPalindromePartial(); } if(palin) cout << "TAK" << endl; else cout << "NIE" << endl; return 0; } |