谨以此题纪念边界测试数据浪费了我多少时间：https://pintia.cn/problem-sets/994805342720868352/problems/994805507225665536
1 #include <iostream> 2 #include <string> 3 #include <vector> 4 #include <algorithm> 5 6 void read(std::vector<int>& _data) 7 { 8 std::string s; 9 std::cin >> s; 10 _data.reserve(s.size()); 11 for (auto c : s) 12 if (c < 'a') 13 _data.push_back(c - '0'); 14 else 15 _data.push_back(c - 'a' + 10); 16 } 17 18 auto convert(const std::vector<int>& _data, uint64_t _radix) 19 { 20 uint64_t res = 0; 21 for (auto i : _data) 22 res = res * _radix + i; 23 return res; 24 } 25 26 uint64_t solve(const std::vector<int>& _data, uint64_t _value) 27 { 28 if (_data.size() == 1) 29 return _data[0] == _value ? _value + 1 : -1; 30 uint64_t radix; 31 for (radix = 2; convert(_data, radix) <= _value; radix *= 2) 32 ; 33 if (radix == 2) 34 return -1; 35 auto begin = std::max<uint64_t>(*std::max_element(_data.begin(), _data.end()) + 1, radix / 2); 36 auto end = radix; 37 while (begin < end) 38 { 39 auto mid = (begin + end) / 2; 40 auto res = convert(_data, mid); 41 if (res > _value) 42 end = mid; 43 else if (res < _value) 44 begin = mid + 1; 45 else 46 return mid; 47 } 48 return -1; 49 } 50 51 int main(int argc, char const *argv[]) 52 { 53 std::vector<int> data; 54 int64_t value; 55 { 56 std::vector<int> source; 57 read(source); 58 read(data); 59 int which; 60 std::cin >> which; 61 if (which == 2) 62 source.swap(data); 63 int radix; 64 std::cin >> radix; 65 value = convert(source, radix); 66 } 67 68 auto res = solve(data, value); 69 if (res == -1) 70 std::cout << "Impossible"; 71 else 72 std::cout << res; 73 74 return 0; 75 }