Depth-First Search
Breadth-First Search
Array
Matrix
Description
Let's play the minesweeper game (Wikipedia , online game )!
You are given an m x n
char matrix board
representing the game board where:
'M'
represents an unrevealed mine,
'E'
represents an unrevealed empty square,
'B'
represents a revealed blank square that has no adjacent mines (i.e., above, below, left, right, and all 4 diagonals),
digit ('1'
to '8'
) represents how many mines are adjacent to this revealed square, and
'X'
represents a revealed mine.
You are also given an integer array click
where click = [clickr , clickc ]
represents the next click position among all the unrevealed squares ('M'
or 'E'
).
Return the board after revealing this position according to the following rules :
If a mine 'M'
is revealed, then the game is over. You should change it to 'X'
.
If an empty square 'E'
with no adjacent mines is revealed, then change it to a revealed blank 'B'
and all of its adjacent unrevealed squares should be revealed recursively.
If an empty square 'E'
with at least one adjacent mine is revealed, then change it to a digit ('1'
to '8'
) representing the number of adjacent mines.
Return the board when no more squares will be revealed.
Example 1:
Input: board = [["E","E","E","E","E"],["E","E","M","E","E"],["E","E","E","E","E"],["E","E","E","E","E"]], click = [3,0]
Output: [["B","1","E","1","B"],["B","1","M","1","B"],["B","1","1","1","B"],["B","B","B","B","B"]]
Example 2:
Input: board = [["B","1","E","1","B"],["B","1","M","1","B"],["B","1","1","1","B"],["B","B","B","B","B"]], click = [1,2]
Output: [["B","1","E","1","B"],["B","1","X","1","B"],["B","1","1","1","B"],["B","B","B","B","B"]]
Constraints:
m == board.length
n == board[i].length
1 <= m, n <= 50
board[i][j]
is either 'M'
, 'E'
, 'B'
, or a digit from '1'
to '8'
.
click.length == 2
0 <= clickr < m
0 <= clickc < n
board[clickr ][clickc ]
is either 'M'
or 'E'
.
Solutions
Solution 1
Python3 Java C++ Go TypeScript
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24 class Solution :
def updateBoard ( self , board : List [ List [ str ]], click : List [ int ]) -> List [ List [ str ]]:
def dfs ( i : int , j : int ):
cnt = 0
for x in range ( i - 1 , i + 2 ):
for y in range ( j - 1 , j + 2 ):
if 0 <= x < m and 0 <= y < n and board [ x ][ y ] == "M" :
cnt += 1
if cnt :
board [ i ][ j ] = str ( cnt )
else :
board [ i ][ j ] = "B"
for x in range ( i - 1 , i + 2 ):
for y in range ( j - 1 , j + 2 ):
if 0 <= x < m and 0 <= y < n and board [ x ][ y ] == "E" :
dfs ( x , y )
m , n = len ( board ), len ( board [ 0 ])
i , j = click
if board [ i ][ j ] == "M" :
board [ i ][ j ] = "X"
else :
dfs ( i , j )
return board
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41 class Solution {
private char [][] board ;
private int m ;
private int n ;
public char [][] updateBoard ( char [][] board , int [] click ) {
m = board . length ;
n = board [ 0 ] . length ;
this . board = board ;
int i = click [ 0 ] , j = click [ 1 ] ;
if ( board [ i ][ j ] == 'M' ) {
board [ i ][ j ] = 'X' ;
} else {
dfs ( i , j );
}
return board ;
}
private void dfs ( int i , int j ) {
int cnt = 0 ;
for ( int x = i - 1 ; x <= i + 1 ; ++ x ) {
for ( int y = j - 1 ; y <= j + 1 ; ++ y ) {
if ( x >= 0 && x < m && y >= 0 && y < n && board [ x ][ y ] == 'M' ) {
++ cnt ;
}
}
}
if ( cnt > 0 ) {
board [ i ][ j ] = ( char ) ( cnt + '0' );
} else {
board [ i ][ j ] = 'B' ;
for ( int x = i - 1 ; x <= i + 1 ; ++ x ) {
for ( int y = j - 1 ; y <= j + 1 ; ++ y ) {
if ( x >= 0 && x < m && y >= 0 && y < n && board [ x ][ y ] == 'E' ) {
dfs ( x , y );
}
}
}
}
}
}
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37 class Solution {
public :
vector < vector < char >> updateBoard ( vector < vector < char >>& board , vector < int >& click ) {
int m = board . size (), n = board [ 0 ]. size ();
int i = click [ 0 ], j = click [ 1 ];
function < void ( int , int ) > dfs = [ & ]( int i , int j ) {
int cnt = 0 ;
for ( int x = i - 1 ; x <= i + 1 ; ++ x ) {
for ( int y = j - 1 ; y <= j + 1 ; ++ y ) {
if ( x >= 0 && x < m && y >= 0 && y < n && board [ x ][ y ] == 'M' ) {
++ cnt ;
}
}
}
if ( cnt ) {
board [ i ][ j ] = cnt + '0' ;
} else {
board [ i ][ j ] = 'B' ;
for ( int x = i - 1 ; x <= i + 1 ; ++ x ) {
for ( int y = j - 1 ; y <= j + 1 ; ++ y ) {
if ( x >= 0 && x < m && y >= 0 && y < n && board [ x ][ y ] == 'E' ) {
dfs ( x , y );
}
}
}
}
};
if ( board [ i ][ j ] == 'M' ) {
board [ i ][ j ] = 'X' ;
} else {
dfs ( i , j );
}
return board ;
}
};
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35 func updateBoard ( board [][] byte , click [] int ) [][] byte {
m , n := len ( board ), len ( board [ 0 ])
i , j := click [ 0 ], click [ 1 ]
var dfs func ( i , j int )
dfs = func ( i , j int ) {
cnt := 0
for x := i - 1 ; x <= i + 1 ; x ++ {
for y := j - 1 ; y <= j + 1 ; y ++ {
if x >= 0 && x < m && y >= 0 && y < n && board [ x ][ y ] == 'M' {
cnt ++
}
}
}
if cnt > 0 {
board [ i ][ j ] = byte ( cnt + '0' )
return
}
board [ i ][ j ] = 'B'
for x := i - 1 ; x <= i + 1 ; x ++ {
for y := j - 1 ; y <= j + 1 ; y ++ {
if x >= 0 && x < m && y >= 0 && y < n && board [ x ][ y ] == 'E' {
dfs ( x , y )
}
}
}
}
if board [ i ][ j ] == 'M' {
board [ i ][ j ] = 'X'
} else {
dfs ( i , j )
}
return board
}
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35 function updateBoard ( board : string [][], click : number []) : string [][] {
const m = board . length ;
const n = board [ 0 ]. length ;
const [ i , j ] = click ;
const dfs = ( i : number , j : number ) => {
let cnt = 0 ;
for ( let x = i - 1 ; x <= i + 1 ; ++ x ) {
for ( let y = j - 1 ; y <= j + 1 ; ++ y ) {
if ( x >= 0 && x < m && y >= 0 && y < n && board [ x ][ y ] === 'M' ) {
++ cnt ;
}
}
}
if ( cnt > 0 ) {
board [ i ][ j ] = cnt . toString ();
return ;
}
board [ i ][ j ] = 'B' ;
for ( let x = i - 1 ; x <= i + 1 ; ++ x ) {
for ( let y = j - 1 ; y <= j + 1 ; ++ y ) {
if ( x >= 0 && x < m && y >= 0 && y < n && board [ x ][ y ] === 'E' ) {
dfs ( x , y );
}
}
}
};
if ( board [ i ][ j ] === 'M' ) {
board [ i ][ j ] = 'X' ;
} else {
dfs ( i , j );
}
return board ;
}
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