Massive Algorithms: Problem A Tic-Tac-Toe-Tomek - Qualification Round 2013

Problem A Tic-Tac-Toe-Tomek - Qualification Round 2013 - Google Code Jam

Dashboard - Qualification Round 2013 - Google Code Jam
Tic-Tac-Toe-Tomek is a game played on a 4 x 4 square board. The board starts empty, except that a single 'T' symbol may appear in one of the 16 squares. There are two players: X and O. They take turns to make moves, with X starting. In each move a player puts her symbol in one of the empty squares. Player X's symbol is 'X', and player O's symbol is 'O'.

After a player's move, if there is a row, column or a diagonal containing 4 of that player's symbols, or containing 3 of her symbols and the 'T' symbol, she wins and the game ends. Otherwise the game continues with the other player's move. If all of the fields are filled with symbols and nobody won, the game ends in a draw. See the sample input for examples of various winning positions.

Given a 4 x 4 board description containing 'X', 'O', 'T' and '.' characters (where '.' represents an empty square), describing the current state of a game, determine the status of the Tic-Tac-Toe-Tomek game going on. The statuses to choose from are:

"X won" (the game is over, and X won)
"O won" (the game is over, and O won)
"Draw" (the game is over, and it ended in a draw)
"Game has not completed" (the game is not over yet)

If there are empty cells, and the game is not over, you should output "Game has not completed", even if the outcome of the game is inevitable.
http://united-coders.com/christian-harms/google-code-jam-2013-tic-tac-toe-tomek-solution/

X. solution with bit masks

The game field has 16 items with 4 states [“.”, “O”, “X”, “T”]. This can be converted into a 32 bit value. And if you choose “O”:1 and “X”:2 then will result “T”:3 with an AND-operation for both in a TRUE!

def solve_with_bits(lines):
    mapping = {".":0, "O": 1, "X":2, "T":3}
    m = 0
    #convert input lines in 32-bit-number!
    for c in lines:
        if mapping.has_key(c):
            m = (m<<2)+mapping[c]
    
    pat = [(4, 0x55, 1, 7),       # 4x, horicontal, 1 bit for O, 8 bit next test
           (4, 0x01010101, 1, 1), # 4x, vert. line, next Vert. only 1 bit 
           (1, 0x01041040, 1, 1), # 1x, /, 1 bit shift
           (1, 0x40100401, 1, 1)  # 1x, \, 1 bit shift
          ]
    #check win situation for O and X
    for loop, hBits, shift1, shift2 in pat:
        for i in range(loop):
            if m & hBits == hBits:
                return "O won"
            hBits = hBits << shift1              # 1 bit shift for X
            if m & hBits == hBits:
                return "X won"
            hBits = hBits << shift2
    if lines.find(".")!=-1:
        return "Game has not completed"
    return "Draw"

X. Using Regular Expression.

This kind of problem can be easy solved with a regex if you use the field in one string:

lines = “XOOX\nOXXO\nOOTX\nOOOX”

import re, sys

pattern = "OOOO|O....O....O....O|O.....O.....O.....O|O...O...O...O"
checkO = re.compile(pattern, re.S)
checkX = re.compile(pattern.replace("O","X"), re.S)
def solve_with_regex(lines):
    #set T to O and test with the O-regex
    if checkO.search(lines.replace("T", "O")):
        return "O won"
    #set T to X and test with the X-regex
    if checkX.search(lines.replace("T", "X")):
        return "X won"
    if lines.find(".")!=-1:
        return "Game has not completed"
    return "Draw"
#solved

IN = file(sys.argv[1])
for t in range(1, int(IN.readline())+1):
    lines = "".join([IN.readline() for x in range(5)])
    print "Case #%d: %s" % (t, solve_with_regex(lines))

Official Analysis
https://code.google.com/codejam/contest/2270488/dashboard#s=a&a=0

def solve(b):
  for c in ['X', 'O']:
    wind1 = True
    wind2 = True
    for x in range(4):
      winh = True
      winv = True
      for y in range(4):
        if b[y][x]!=c and b[y][x]!='T': winv = False
        if b[x][y]!=c and b[x][y]!='T': winh = False
      if winh or winv: return c + ' won'
      if b[x][x]!=c and b[x][x]!='T': wind1 = False
      if b[3-x][x]!=c and b[3-x][x]!='T': wind2 = False
    if wind1 or wind2: return c + ' won'

  for x in range(4):
    for y in range(4):
      if b[y][x]=='.': return 'Game has not completed'

  return 'Draw'

https://gist.github.com/KuoE0/5381830


	bool checkFull( char board[][ 10 ] ) {

	for ( int i = 0; i < 4; ++i )
	for ( int j = 0; j < 4; ++j )
	if ( board[ i ][ j ] == '.' )
	return false;
	return true;
	}

	bool checkRowCol( char board[][ 10 ], char k, int rc, bool dir ) {

	int cnt = 0, T = 0;

	for ( int i = 0; i < 4; ++i ) {
	char c = board[ dir ? i : rc ][ dir ? rc : i ];
	cnt += c == k ? 1 : 0;
	T += c == 'T' ? 1 : 0;
	}
	return cnt == 4 \|\| ( cnt == 3 && T == 1 );
	}

	bool checkDiagonal( char board[][ 10 ], char k, bool dir ) {

	int cnt = 0, T = 0;

	for ( int i = 0; i < 4; ++i ) {
	int c = board[ i ][ dir ? 3 - i : i ];

	cnt += c == k ? 1 : 0;
	T += c == 'T' ? 1 : 0;
	}
	return cnt == 4 \|\| ( cnt == 3 && T == 1 );
	}


	bool checkWin( char board[][ 10 ], char k ) {
	for ( int i = 0; i < 4; ++i )
	if ( checkRowCol( board, k, i, 0 ) \|\| checkRowCol( board, k, i, 1 ) )
	return true;
	for ( int i = 0; i < 2; ++i )
	if ( checkDiagonal( board, k, i ) )
	return true;
	return false;
	}


	if ( checkWin( board, 'X' ) ) printf( "Case #%d: X won\n", test + 1 );
	else if ( checkWin( board, 'O' ) )
	printf( "Case #%d: O won\n", test + 1 );
	else if ( !checkFull( board ) )
	printf( "Case #%d: Game has not completed\n", test + 1 );
	else
	printf( "Case #%d: Draw\n", test + 1 );

http://toughprogramming.blogspot.com/2013/04/code-jam-2013-qualification-round.html
Use int score.

     private static void checkScore(char[][] board, int caseNum,  
                boolean notComplete) throws IOException {  
           // TODO Auto-generated method stub  
           // check diagonals first  
           // first diagonal  
           int j = 0;  
           int xcount = 1;  
           int ycount = 1;  
           boolean tFound = false;  
           for (int i = 0; i < 4; ++i) {  
                if (board[i][j] == 'T') {  
                     ++xcount;  
                     ++ycount;  
                } else if (board[i][j] == 'X') {  
                     ++xcount;  
                } else if (board[i][j] == 'O') {  
                     ++ycount;  
                }  
                ++j;  
           }  
           if (xcount == 5) {  
                writer.write("Case #" + (caseNum + 1) + ": X won");  
                writer.newLine();  
                return;  
           }  
           if (ycount == 5) {  
                writer.write("Case #" + (caseNum + 1) + ": O won");  
                writer.newLine();  
                return;  
           }  
           // ///////////////////////////////////////////////////////////////////////  
           // second diagonal  
           j = 3;  
           xcount = 1;  
           ycount = 1;  
           tFound = false;  
           for (int i = 0; i < 4; ++i) {  
                if (board[i][j] == 'T') {  
                          ++xcount;  
                          ++ycount;  
                } else if (board[i][j] == 'X') {  
                          ++xcount;  
                } else if (board[i][j] == 'O') {  
                          ++ycount;  
                     }  
                --j;  
           }  
           if (xcount == 5) {  
                writer.write("Case #" + (caseNum + 1) + ": X won");  
                writer.newLine();  
                return;  
           }  
           if (ycount == 5) {  
                writer.write("Case #" + (caseNum + 1) + ": O won");  
                writer.newLine();  
                return;  
           }  
           // ////////////////////////////////////////////////////////////////////////  
           // checking rows and cols  
           for (int i = 0; i < 4; ++i) {  
                xcount = 1;  
                ycount = 1;  
                tFound = false;  
                for (int row = 0; row < 4; ++row) {  
                     if (board[row][i] == 'T') {  
                          ++xcount;  
                          ++ycount;  
                     } else if (board[row][i] == 'X') {  
                          ++xcount;  
                     } else if (board[row][i] == 'O') {  
                          ++ycount;  
                     }  
                }  
                if (xcount == 5) {  
                     writer.write("Case #" + (caseNum + 1) + ": X won");  
                     writer.newLine();  
                     return;  
                }  
                if (ycount == 5) {  
                     writer.write("Case #" + (caseNum + 1) + ": O won");  
                     writer.newLine();  
                     return;  
                }  
                xcount = 1;  
                ycount = 1;  
                tFound = false;  
                for (int col = 0; col < 4; ++col) {  
                     if (board[i][col] == 'T') {  
                          ++xcount;  
                          ++ycount;  
                     } else if (board[i][col] == 'X') {  
                          ++xcount;  
                     } else if (board[i][col] == 'O') {  
                          ++ycount;  
                     }  
                }  
                if (xcount == 5) {  
                     writer.write("Case #" + (caseNum + 1) + ": X won");  
                     writer.newLine();  
                     return;  
                }  
                if (ycount == 5) {  
                     writer.write("Case #" + (caseNum + 1) + ": O won");  
                     writer.newLine();  
                     return;  
                }  
           }  
           if (notComplete) {  
                writer.write("Case #" + (caseNum + 1) + ": Game has not completed");  
                writer.newLine();  
                return;  
           }  
           writer.write("Case #" + (caseNum + 1) + ": Draw");  
           writer.newLine();  
           return;  
      }

http://arxoclay.blogspot.com/2013/04/google-code-jam-tic-tac-toe-tomek.html

def hasWon(boardState, winningSymbol):

    # Horizontal Check

    for row in range(len(boardState)):

        rowWinner = True

        for column in range(len(boardState)):

            if boardState[row][column] == winningSymbol or boardState[row][column] == "T":

                continue

            else:

                rowWinner = False

                break

        if rowWinner == True:

            return True

    # Vertical Check

    for column in range(len(boardState)):

        columnWinner = True

        for row in range(len(boardState)):

            if boardState[row][column] == winningSymbol or boardState[row][column] == "T":

                continue

            else:

                columnWinner = False

                break

        if columnWinner == True:

            return True

    # Diagonal Check

    if (boardState[0][0] == winningSymbol or boardState[0][0] == "T") and(boardState[1][1] == winningSymbol or boardState[1][1] == "T") and(boardState[2][2] == winningSymbol or boardState[2][2] == "T") and(boardState[3][3] == winningSymbol or boardState[3][3] == "T"):

        return True

    if (boardState[0][3] == winningSymbol or boardState[0][3] == "T") and(boardState[1][2] == winningSymbol or boardState[1][2] == "T") and(boardState[2][1] == winningSymbol or boardState[2][1] == "T") and(boardState[3][0] == winningSymbol or boardState[3][0] == "T"):

        return True

def hasEmptySpaces(boardState):

    for row in range(len(boardState)):

        for column in range(len(boardState)):

            if boardState[row][column] == ".":

                return True

    return False

def ticTacToeTomek(boardState):

    if hasWon(boardState, "X"):

        return "X won"

    elif hasWon(boardState, "O"):

        return "O won"

    elif hasEmptySpaces(boardState):

        return "Game has not completed"

    return "Draw"

Read full article from Dashboard - Qualification Round 2013 - Google Code Jam

Problem A Tic-Tac-Toe-Tomek - Qualification Round 2013 - Google Code Jam

X. solution with bit masks

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