connect 4

/**
 * Homework 7
 * Connect Four Game
 *
 * Ben Margolis - 10235419
 * Erik Veloz Perez - 00908094
 *
 * This program will run a game of Connect Four with the input from one player,
 * against the computer (AI). The program will either terminate after a win or
 * at the players request once the game is done.
 **/

#include <iostream>
#include <vector>
#include <cassert>

using namespace std;
using Row = vector<char>;
using Board = vector<Row>;


bool connect_col(Board b, int col);
bool connect_vert(Board b);

bool connect_single_fd(Board b, int row, int col);
bool connect_fd_row(Board b, int row);
bool connect_forward_diag(Board b);

bool connect_single_bd(Board b, int row, int col);
bool connect_bd_row(Board b, int row);
bool connect_backward_diag(Board b);


bool connect_diag(Board b);


bool connect_four(Board b);

void run();
void test();


int main() {
    char t;

    cout << "Enter [t] to test, or any other character to run." << endl;
    cin >> t;
    if(t == 't') {
      test();
    } else {
      run();
    }
}


void run() {
    Board gb;
    gb = {
        { {' '}, {' '}, {' '}, {' '}, {' '}, {' '}, {' '} },
        { {' '}, {' '}, {' '}, {' '}, {' '}, {' '}, {' '} },
        { {' '}, {' '}, {' '}, {' '}, {' '}, {' '}, {' '} },
        { {' '}, {' '}, {' '}, {' '}, {' '}, {' '}, {' '} },
        { {' '}, {' '}, {' '}, {' '}, {' '}, {' '}, {' '} },
        { {' '}, {' '}, {' '}, {' '}, {' '}, {' '}, {' '} }
    };
}

void test() {

}


// Checks a single column for a win
bool connect_col(Board b, int col) {
    int i = 0;

    while(i < b.size() - 3) {
        if( b[i][col] == b[i+1][col] &&
            b[i+1][col] == b[i+2][col] &&
            b[i+2][col] == b[i+3][col] ) {
            return true;
        }
        i = i + 1;
    }
    return false;
}


bool connect_vert(Board b) {
    int i = 0;
    while(i < b[0].size()) {
        if(connect_col(b, i)){
            return true;
        }
        i = i + 1;
    }
    return false;
}
// checks a single set of four spaces for a forward diag connect four
// Assumes valid input


bool connect_single_fd(Board b, int row, int col) {
    return b[row][col]     == b[row+1][col-1] &&
           b[row+1][col-1] == b[row+2][col-2] &&
           b[row+2][col-2] == b[row+3][col-3];
}



bool connect_fd_row(Board b, int row) {
    int i = 3;
    while(i < 7) {
        if(connect_single_fd(b, row, i)){
            return true;
        }
        i = i + 1;
    }
    return false;
}



bool connect_forward_diag(Board b) {
    int i = 0;

    while(i < 3) {
        if(connect_fd_row(b, i)) {
            return true;
        }
        i = i + 1;
    }
    return false;
}

// checks a single set of four spaces for a backwards diag connect four
// Assumes valid input

bool connect_single_bd(Board b, int row, int col) {
    return b[row][col]     == b[row+1][col+1] &&
           b[row+1][col+1] == b[row+2][col+2] &&
           b[row+2][col+2] == b[row+3][col+3];
}

bool connect_bd_row(Board b, int row) {
    int i = 0;
    while(i < 4) {
        if(connect_single_bd(b, row, i)){
            return true;
        }
        i = i + 1;
    }
    return false;
}

bool connect_backward_diag(Board b) {
    int i = 0;

    while(i < 3) {
        if(connect_bd_row(b, i)) {
            return true;
        }
        i = i + 1;
    }
    return false;
}


bool connect_diag(Board b) {
    return connect_forward_diag(b) || connect_backward_diag(b);
}



bool connect_four(Board b) {
    return /*connect_across() ||*/ connect_vert(b) || connect_diag(b);
}