C++ A* Search

#pragma once #include <iostream> class String { private: char* array; unsigned int _capacity; unsigned int _size; public: /** Constructors */ String(); String(char*); String(char); /** Destructors */ ~String(); /** at(int position) * Returns the character at the given position, throws an exception if the * position is out of bounds. * O(?) */ char at(int) const; /** empty() * Returns whether or not the string is empty. * O(?) */ bool empty() const; /** size() * Returns the number of characters in the string. */ unsigned int size() const; /** capacity() * Returns the number of characters that the string can hold. * O(?) */ unsigned int capacity() const; /** reserve(int extra) * Reserves extra amount of characters, extending the capacity of the string. * O(?) */ void reserve(unsigned int); /** insert(char c, int index) * Inserts the given character `c` into the string at the given index. * If the index is out of bounds the character should appended / prepended. * O(?) */ void insert(char, int); /** erase(char) * Erases all copies of the given character from the string. * O(?) */ void erase(char); /** clear() * Clears the contents of the string. */ void clear(); /** remove(int index) * Removes the character at the given index. * O(?) */ void remove(int); /** pop_back * Pops the last character off. */ char pop_back(); /** append(char) * Appends the given character to the string. * O(?) */ void append(char); /** prepend(char) * Prepends the given character to the string. * O(?) */ void prepend(char); /** compare(char* or String) * Returns whether or not the string is equal with the one given. * O(?) */ bool compare(char*) const; bool compare(const String&) const; /** concate(char* or String) * Concatenates the string with the given character array, or string. * O(?) */ void concatenate(char*); void concatenate(String&); /** find(char* or char or String) * Returns the index of the first occurrence of the character array, char, or * string given. Should return length if not found. * O(?) */ unsigned int find(char*, int start = 0) const; unsigned int find(char, int start = 0) const; unsigned int find(String&, int start = 0) const; /** reverse() * Reverses the string in-place. * O(?) */ void reverse(); /** shift(int) * Shifts all characters ASCII values in the array upwards or downwards by the * amount given. This method should also prevent characters from becoming * null, or exceeding the ASCII range. * O(?) */ void shift(int); /** toInt() * Returns the string as an integer, if it can be represented as one. * Otherwise throws an exception * O(?) */ int toInt() const; /** substr(start, end) * Returns the string contained between [start, end). * O(?) */ String substr(int, int) const; /** print(output stream) * Prints the contents of the string to the given output. */ void print(std::ostream& oss = std::cout) const; /** cstr() * Returns a c-style string. */ char* cstr() const { return this->array; }; friend std::ostream& operator<<(std::ostream& oss, const String& str); };