'X'
and 'O'
(the letter O), capture all regions surrounded by 'X'
.'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
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还是深度搜索连通子图类的问题
类似题200. Number of Islands(重要)
class Solution {
public:
void solve(vector<vector<char>>& board) {
int i,j;
int row=board.size();
if(!row)
return;
int col=board[0].size();
for(i=0;i<row;i++){
check(board,i,0,row,col);
if(col>1)
check(board,i,col-1,row,col);
}
for(j=1;j+1<col;j++){
check(board,0,j,row,col);
if(row>1)
check(board,row-1,j,row,col);
}
for(i=0;i<row;i++)
for(j=0;j<col;j++)
if(board[i][j]=='O')
board[i][j]='X';
for(i=0;i<row;i++)
for(j=0;j<col;j++)
if(board[i][j]=='1')
board[i][j]='O';
}
void check(vector<vector<char> >&vec,int i,int j,int row,int col){
if(vec[i][j]=='O'){
vec[i][j]='1';
if(i>1)
check(vec,i-1,j,row,col);
if(j>1)
check(vec,i,j-1,row,col);
if(i+1<row)
check(vec,i+1,j,row,col);
if(j+1<col)
check(vec,i,j+1,row,col);
}
}
};