标签:des style blog color strong cti
Problem Description:
Given a 2D board containing ‘X‘
and ‘O‘
, capture all regions surrounded by ‘X‘
.
A region is captured by flipping all ‘O‘
s into ‘X‘
s in that surrounded region.
For example,
X X X X X O O X X X O X X O X X
After running your function, the board should be:
X X X X X X X X X X X X X O X X
1 public void solve(char[][] board) { 2 Stack<Integer> sx = new Stack<Integer>(); 3 Stack<Integer> sy = new Stack<Integer>(); 4 5 if (board == null || board.length == 0) return; 6 if (board[0].length == 0) return; 7 8 int row = board.length; 9 int col = board[0].length; 10 11 for (int i = 0; i < row; i++) { 12 if (board[i][0] == ‘O‘) { 13 sx.push(i); 14 sy.push(0); 15 } 16 17 if (board[i][col - 1] == ‘O‘) { 18 sx.push(i); 19 sy.push(col - 1); 20 } 21 } 22 23 for (int j = 0; j < col; j++) { 24 if (board[0][j] == ‘O‘) { 25 sx.push(0); 26 sy.push(j); 27 } 28 29 if (board[row - 1][j] == ‘O‘) { 30 sx.push(row - 1); 31 sy.push(j); 32 } 33 } 34 while (! sx.isEmpty()) { 35 int x = sx.pop(); 36 int y = sy.pop(); 37 38 board[x][y] = ‘#‘; 39 40 if (y > 0 && board[x][y - 1] == ‘O‘) { 41 sx.push(x); 42 sy.push(y - 1); 43 } 44 45 if (y < col - 1 && board[x][y + 1] == ‘O‘) { 46 sx.push(x); 47 sy.push(y + 1); 48 } 49 50 if (x > 0 && board[x - 1][y] == ‘O‘) { 51 sx.push(x - 1); 52 sy.push(y); 53 } 54 if (x < row - 1 && board[x + 1][y] == ‘O‘) { 55 sx.push(x + 1); 56 sy.push(y); 57 } 58 59 } 60 for (int i = 0; i < row; i++) 61 for (int j = 0; j < col; j++) { 62 if (board[i][j] == ‘#‘) { 63 board[i][j]= ‘O‘; 64 } else { 65 board[i][j] = ‘X‘; 66 } 67 } 68 69 }
Problem Surrounded Regions,布布扣,bubuko.com
标签:des style blog color strong cti
原文地址:http://www.cnblogs.com/liew/p/3815097.html