Finding 5 in a row - ios

Question

Background:
Im building a game "kinda" like connect 4.
I have most of it working, the only part I'm stuck at now is determining if there are 5 of the same colors in a row (left,right,up,down & diagonal)
Question:
How can I get the code to loop and see if there are 5 pieces in a row with the same color in any direction.
Note - Each turn is played by moving one piece on the board to a new position and than 3 new pieces come into play.
That means that it would have to check for a match of 5 after the turn and also after the 3 new pieces get randomly placed onto the board.
Thank you!
My code for the game so far is..
ViewController(.m)
#import "ViewController.h"
#import "BoardCell.h"
#import <QuartzCore/QuartzCore.h>
#interface ViewController ()
#property (strong,nonatomic) NSArray *imageNames;
#property (strong,nonatomic) NSMutableArray *board;
#property NSInteger lastMove;
#define BOARDWIDTH 9
#define BOARDHEIGHT 9
#end
static int moves[]={-BOARDWIDTH,-1,1,BOARDWIDTH};
bool preSelect;
BoardCell *startCell;
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
preSelect = NO;
self.imageNames = #[#"marble_red",#"marble_blue",#"marble_purple",#"marble_orange",#"marble_green"];
self.board = [NSMutableArray new];
for (int y=0; y < BOARDWIDTH; y++) {
for (int x = 0; x < BOARDHEIGHT; x++) {
UIButton * button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
button.frame = CGRectMake(5+ 35 * x, 100 + 35 * y, 30, 30);
button.tag = y*BOARDWIDTH+x;
//[button setTitle:[NSString stringWithFormat:#"%ld", button.tag] forState:UIControlStateNormal];
button.selected = NO;
[button.layer setCornerRadius:15];
[button setBackgroundColor:[UIColor colorWithWhite:.7 alpha:.5]];
[button addTarget:self action:#selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview: button];
[self.board addObject:[[BoardCell alloc] initWithButton:button]];
}
}
self.lastMove=arc4random_uniform(BOARDWIDTH*BOARDHEIGHT);
UIButton *button=(UIButton *)[self.view viewWithTag:self.lastMove];
[button setBackgroundImage:[UIImage imageNamed:#"greensquare"] forState:UIControlStateNormal];
[self addRandoms:3];
}
-(void) addRandoms:(NSInteger)randomCount {
for (int i = 0; i < randomCount; i++) {
int space = arc4random_uniform(BOARDWIDTH*BOARDHEIGHT);
BoardCell *cell=self.board[space];
if (!cell.occupied) {
int pic = arc4random_uniform((u_int32_t)self.imageNames.count);
NSString *string = [self.imageNames objectAtIndex:pic];
NSString *highlighted = [NSString stringWithFormat:#"%#_highlighted",string];
NSLog(#"HIGHLIGHTED = %#",highlighted);
[cell.button setBackgroundImage:[UIImage imageNamed:string] forState:UIControlStateNormal];
[cell.button setTitleColor:[UIColor lightGrayColor] forState:UIControlStateNormal];
[cell.button setTitleColor:[UIColor blackColor] forState:UIControlStateSelected];
cell.button.selected = NO;
cell.occupied=YES;
}
else {
i--;
}
}
}
-(void)buttonPressed:(UIButton *)button
{
NSInteger buttonId=button.tag;
BoardCell *cell=self.board[buttonId];
if (!preSelect) {
if (cell.occupied) {
//cell.button.selected = YES;
[[cell.button layer] setBorderWidth:3.5f];
[cell.button.layer setBorderColor:[[UIColor colorWithWhite:.85 alpha:.7]CGColor]];
cell.button.highlighted = YES;
preSelect = YES;
self.lastMove = buttonId;
startCell = cell;
}else{
cell.button.selected = NO;
cell.button.highlighted = NO;
[cell.button.layer setBorderColor:[[UIColor clearColor]CGColor]];
}
}else{
NSLog(#"SECOND STEP");
if (!cell.occupied) {
BoardCell *startCell=self.board[self.lastMove];
startCell.occupied=NO;
if ([self validMoveFromSquare:self.lastMove toDestination:buttonId]) {
[cell.button setBackgroundImage:[startCell.button backgroundImageForState:UIControlStateNormal]
forState:UIControlStateNormal];
[startCell.button setBackgroundImage:[UIImage imageNamed:#""] forState:UIControlStateNormal];
NSLog(#"FROM %ld, TO %ld",(long)self.lastMove,(long)buttonId);
cell.button.selected = NO;
cell.button.highlighted = NO;
startCell.button.selected = NO;
startCell.button.highlighted = NO;
self.lastMove=buttonId;
cell.occupied=YES;
preSelect = NO;
[self addRandoms:3];
}else{
startCell.occupied=YES;
preSelect = NO;
cell.button.selected = NO;
cell.button.highlighted = NO;
startCell.button.selected = NO;
startCell.button.highlighted = NO;
NSLog(#" INVALID FROM %ld, TO %ld",(long)self.lastMove,(long)buttonId);
}
}
preSelect = NO;
cell.button.selected = NO;
cell.button.highlighted = NO;
startCell.button.selected = NO;
startCell.button.highlighted = NO;
[cell.button.layer setBorderColor:[[UIColor clearColor]CGColor]];
[startCell.button.layer setBorderColor:[[UIColor clearColor]CGColor]];
}
}
-(BOOL) validMoveFromSquare:(NSInteger)startSquare toDestination:(NSInteger)destination {
for (int limit=1;limit<10;limit++ ) {
NSMutableIndexSet *visitList=[NSMutableIndexSet new];
if ([self DFSFromStart:startSquare toGoal:destination withLimit:limit andVisitList:visitList]) {
return YES;
}
}
return NO;
}
-(BOOL) DFSFromStart:(NSInteger)start toGoal:(NSInteger)goal withLimit:(NSInteger)limit andVisitList:(NSMutableIndexSet *)visitList {
if (limit >=0) {
if (((BoardCell *)self.board[start]).occupied) {
NSLog(#"Self Board = %#",self.board[start]);
return NO;
}
[visitList addIndex:start];
for (int i=0;i<4;i++) {
NSInteger nextPosition=start+moves[i];
NSLog(#"Next spot = %ld",(long)nextPosition);
if (nextPosition == goal) {
return YES;
}
if (nextPosition >=0 && nextPosition < BOARDWIDTH*BOARDHEIGHT) {
if (![visitList containsIndex:nextPosition]) {
if ([self DFSFromStart:nextPosition toGoal:goal withLimit:limit-1 andVisitList:visitList]) {
return YES;
}
}
}
}
}
return NO;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
BoardCell.m
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
#interface BoardCell : NSObject
#property (weak,nonatomic,readonly) UIButton *button;
#property BOOL occupied;
-(id) initWithButton:(UIButton *)button;
#end
Thank you again!

Answer 1

You can use a recursive algorithm to work in each of the eight directions until you hit a boundary or a different color -
-(void) clearRunsOfColor:(Colors)color fromPoint:(NSInteger)startPoint {
NSInteger left=[self runFromStart:startPoint-1 ofColor:color inDirection:-1];
NSInteger right=[self runFromStart:startPoint+1 ofColor:color inDirection:1];
BOOL cleared=NO;
if (left+right+1 >4) {
[self clearBoardFromStart:startPoint-1 inDirection:-1 forLength:left];
[self clearBoardFromStart:startPoint+1 inDirection:1 forLength:right];
cleared=YES;
}
NSInteger up=[self runFromStart:startPoint-BOARDWIDTH ofColor:color inDirection:-BOARDWIDTH];
NSInteger down=[self runFromStart:startPoint+BOARDWIDTH ofColor:color inDirection:BOARDWIDTH];
if (up+down+1 > 4) {
[self clearBoardFromStart:startPoint-BOARDWIDTH inDirection:-BOARDWIDTH forLength:up];
[self clearBoardFromStart:startPoint+BOARDWIDTH inDirection:BOARDWIDTH forLength:down];
cleared=YES;
}
NSInteger NW=[self runFromStart:startPoint-BOARDWIDTH-1 ofColor:color inDirection:-BOARDWIDTH-1];
NSInteger SE=[self runFromStart:startPoint+BOARDWIDTH+1 ofColor:color inDirection:+BOARDWIDTH+1];
if (NW+SE+1 > 4) {
[self clearBoardFromStart:startPoint-BOARDWIDTH-1 inDirection:-BOARDWIDTH-1 forLength:NW];
[self clearBoardFromStart:startPoint+BOARDWIDTH+1 inDirection:BOARDWIDTH+1 forLength:SE];
cleared=YES;
}
NSInteger NE=[self runFromStart:startPoint-BOARDWIDTH+1 ofColor:color inDirection:-BOARDWIDTH+1];
NSInteger SW=[self runFromStart:startPoint+BOARDWIDTH-1 ofColor:color inDirection:+BOARDWIDTH-1];
if (NE+SW+1 > 4) {
[self clearBoardFromStart:startPoint-BOARDWIDTH+1 inDirection:-BOARDWIDTH+1 forLength:NE];
[self clearBoardFromStart:startPoint+BOARDWIDTH-1 inDirection:BOARDWIDTH-1 forLength:SW];
cleared=YES;
}
if (cleared) {
[self occupyCell:startPoint withPiece:nil];
}
}
-(void) clearBoardFromStart:(NSInteger)start inDirection:(NSInteger)direction forLength:(NSInteger) length {
NSInteger pos=start;
for (int i=0;i<length;i++) {
[self occupyCell:pos withPiece:nil];
pos+=direction;
}
}
-(NSInteger) runFromStart:(NSInteger)start ofColor:(Colors)color inDirection:(NSInteger)direction {
if ([self inBounds:start]) {
BoardCell *thisCell=self.board[start];
if (thisCell.gamepiece != nil && thisCell.gamepiece.color == color) {
if ([self validDestination:start+direction withMove:(int)direction fromSquare:start]) {
return ([self runFromStart:start+direction ofColor:color inDirection:direction]+1);
}
else {
return 1;
}
}
}
return 0;
}
-(BOOL) inBounds:(NSInteger) position {
if (position >=0 && position < BOARDHEIGHT*BOARDWIDTH) {
return YES;
}
else {
return NO;
}
}

Answer 2

None of the code below is tested for correctness.
You could update your BoardCell class like so:
typedef enum {
TopLeft, Top, TopRight,
Left, Right,
BottomLeft, Bottom, BottomRight,
NumberOfDirections
} BoardCellAdjacentDirection;
#interface BoardCell
- (void)addAdjacentCell:(BoardCell *)cell forDirection:(BoardCellAdjacentDirection)direction;
- (NSInteger)occupiedCellsInDirection:(BoardCellAdjacentDirection)direction;
#end
#implementation BoardCell {
NSMutableArray *adjacentCells;
}
- (instancetype)init {
if (self = [super init]) {
adjacentCells = [[NSMutableArray alloc] init];
for (NSInteger i = 0; i < (NSInteger)NumberOfDirections; i++) {
[adjacentCells addObject:[NSNull null]];
}
}
return self;
}
- (void)addAdjacentCell:(BoardCell *)cell forDirection:(BoardCellAdjacentDirection)direction {
[adjacentCells setObject:cell atIndex:(NSInteger)direction];
}
- (NSInteger)occupiedCellsInDirection:(BoardCellAdjacentDirection)direction {
if (!self.occupied) return 0;
if (adjacentCells[direction] == [NSNull null]) return 1;
return [adjacentCells[direction] occupiedCellsInDirection:direction]+1;
}
#end
Wherever you create your BoardCell objects, you'll need to add the appropriate adjacent cells. You'll also probably want to put in some sanity checks to make sure that cell adjacency is a two-way relationship (i.e. cell A is left-adjacent to B and B is right-adjacent to A).
Edit You'll probably also want to add a method to determine if you've injected a cell into the centre of a line.
typedef enum {
BackSlash,
ForwardSlash,
Vertical,
Horizontal
} BoardCellAxis;
...
- (NSInteger)occupiedCellsOnAxis:(BoardCellAxis)axis {
switch (axis) {
case BackSlash:
return MAX(0, [self occupiedCellsInDirection:TopLeft]
+ [self occupiedCellsInDirection:BottomRight]
- 1); // Don't count yourself twice.
case ForwardSlash:
return MAX(0, [self occupiedCellsInDirection:TopRight]
+ [self occupiedCellsInDirection:BottomLeft]
- 1); // Don't count yourself twice.
case Vertical:
return MAX(0, [self occupiedCellsInDirection:Top]
+ [self occupiedCellsInDirection:Bottom]
- 1); // Don't count yourself twice.
case Horizontal:
return MAX(0, [self occupiedCellsInDirection:Left]
+ [self occupiedCellsInDirection:Right]
- 1); // Don't count yourself twice.
}
}