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Hi All,
I've already had some help on this forum, I'm so glad I found it -- I'm working on an assignment and I'm just struggling with a concept as I'm quite a newcomer with C++.
We are being taught to use doubly-linked lists rather than arrays (therefore the method to traverse between lists to access data is rather inefficient as it involves starting from the beginning each time) - and I'd like some suggestions on how to get started, as I can't think of the right way to do it... maybe to utilise a "row number" for the horizontal lists... I'm not sure.
Anyway, suggestions are very welcome, and I will post my code (it's all in one cpp file). Essentially I need to be able to traverse the list up and down so that I can see all the spaces to the immediate left, top and bottom of a position in one of the rows.
The function "calculate_metrics" alllll the way at the bottom is what I'm up to - I'm so close to getting it all functional!
Code:#include <iostream> #include <fstream> #include <list> #include <ctype.h> #include <cstdlib> using namespace std; class row { private: list<char> row_chars; int row_number; public: row(int number) { row_number = number; } void store_chars(char ch); void new_row(); void print_row(); bool is_match(char data); void clear_row(); bool is_char_valid(); bool is_outside_maze(char findData); bool check_counts(int hash, int s, int f); int get_row_number(); }; void load_maze(list<row> &maze_rows, row &row_chars, const string &filein); void print_maze(list<row> &maze_rows); bool find_char(const char &findData, list<row>::iterator &itr, list<row> &maze_rows); int count_char(const char &findData, list<row>::iterator &itr, list<row> &maze_rows); bool is_maze_valid(list<row>::iterator &itr, list<row> &maze_rows); bool is_outside(const char &findData, list<row>::iterator &itr, list<row> &maze_rows); int test_maze(list<row> &maze_rows); void calculate_metrics(list<row> &maze_rows); int main (int argc, char *argv[]) { string filein; list<row> maze_rows; row row_chars(1); //Make sure a maze file was provided if (argc != 2) { cout << "Must supply 1 argument to this program\n"; return 0; } filein = argv[1]; //Loading the file into lists... load_maze(maze_rows, row_chars, filein); //Running the tests on the lists... if(test_maze(maze_rows) == 0) { cout << "Unable to load maze " << filein << " \n"; exit(0); } print_maze(maze_rows); //Calculate and print the maze metrics... calculate_metrics(maze_rows); return 0; } void row::store_chars(char ch) { row_chars.push_back(ch); } void row::new_row() { row_number++; } void row::print_row() { for(list<char>::iterator list_iter = row_chars.begin(); list_iter != row_chars.end(); list_iter++) cout << *list_iter; } bool row::is_match(char data) { //Return false if it cannot find the provided char in the row for(list<char>::iterator list_iter = row_chars.begin(); list_iter != row_chars.end(); list_iter++) { if(*list_iter == data) return true; } return false; } void row::clear_row() { row_chars.clear(); } bool row::is_char_valid() { //Return true if all the chars match up with one of the specified characters for(list<char>::iterator list_iter = row_chars.begin(); list_iter != row_chars.end(); list_iter++) { if(*list_iter == '#' || *list_iter == 's' || *list_iter == 'f' || *list_iter == ' ' || *list_iter == '\n') continue; else return false; } return true; } bool row::is_outside_maze(char findData) { //Return true if the char is outside the maze int hash_count, s_count, f_count; hash_count = s_count = f_count = 0; for(list<char>::iterator list_iter = row_chars.begin(); list_iter != row_chars.end(); list_iter++) { if(*list_iter == '#') hash_count++; if(*list_iter == 's') s_count++; if(*list_iter == 'f') f_count++; if(check_counts(hash_count, s_count, f_count)) continue; else return true; } return false; } bool row::check_counts(int hash, int s, int f) { if((s > 0 || f > 0) && hash == 0) return false; else return true; } int row::get_row_number() { return row_number; } void load_maze(list<row> &maze_rows, row &row_chars, const string &filein) { ifstream fin; char ch; //open stream to filein fin.open(filein.c_str()); if (!fin) { cerr << "Unable to load maze " << filein << " \n"; exit(0); } while (!fin.eof()) { fin.get(ch); row_chars.store_chars(ch); if(ch == '\n') { maze_rows.push_back(row_chars); row_chars.clear_row(); row_chars.new_row(); } } fin.close(); } void print_maze(list<row> &maze_rows) { for(list<row>::iterator list_iter = maze_rows.begin(); list_iter != maze_rows.end(); list_iter++) list_iter->print_row(); } bool find_char(const char &findData, list<row>::iterator &itr, list<row> &maze_rows) { // Check if char is found in list for (itr = maze_rows.begin(); itr != maze_rows.end(); itr++) { if (itr->is_match(findData)) return true; } return false; } int count_char(const char &findData, list<row>::iterator &itr, list<row> &maze_rows) { // Check how many times the char occurs in the row int data_count = 0; for (itr = maze_rows.begin(); itr != maze_rows.end(); itr++) { if (itr->is_match(findData)) data_count++; } return data_count; } bool is_maze_valid(list<row>::iterator &itr, list<row> &maze_rows) { // Testing if chars in the maze are valid for (itr = maze_rows.begin(); itr != maze_rows.end(); itr++) { if (itr->is_char_valid()) continue; else { cout << "invalid character in maze\n"; return false; } } return true; } bool is_outside(const char &findData, list<row>::iterator &itr, list<row> &maze_rows) { //Testing if char is placed inside or outside of the maze for (itr = maze_rows.begin(); itr != maze_rows.end(); itr++) { if (itr->is_outside_maze(findData)) return true; } return false; } int test_maze(list<row> &maze_rows) { list<row>::iterator list_iter; //Testing to see if 's' is contained in the maze... if(!find_char('s', list_iter, maze_rows)) { cout << "Error - no start found in maze"; return(0); } //Testing to see if 'f' is contained in the maze... if(!find_char('f', list_iter, maze_rows)) { cout << "Error - no finish found in maze"; return(0); } //Testing to see if maze contains valid characters... if(!is_maze_valid(list_iter, maze_rows)) { return(0); } //Testing to see if there is only one 's' and 'f' // contained in the maze... if(count_char('s', list_iter, maze_rows) != 1) { cout << "Error - multiple start found in maze\n"; return(0); } if (count_char('f', list_iter, maze_rows) != 1) { cout << "Error - multiple finish found in maze\n"; return(0); } //Testing to see if 's' or 'f' is declared // outside of the maze... if(is_outside('s', list_iter, maze_rows)) { cout << "Error - start declared outside of maze\n"; return(0); } if(is_outside('f', list_iter, maze_rows)) { cout << "Error - finish declared outside of maze\n"; return(0); } return(1); } void calculate_metrics(list<row> &maze_rows) { /*Calculate the total number of branches in the maze*/ /*Calculate the total number of dead ends in the maze*/ int branches, dead_ends; branches = dead_ends = 0; cout << "\nNumber of branches in maze is " << branches << "\n"; cout << "Number of dead-ends in maze is " << dead_ends << "\n"; }
Originally Posted by Bubba 
