/
SurroundedRegions.cpp
61 lines (58 loc) · 1.46 KB
/
SurroundedRegions.cpp
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/**
* 130. Surrounded Regions
*/
#include "inc/common.h"
void dfs(int x, int y, vector<vector<char> >& board) {
if(x < 0 || x >= board.size() || y < 0 || y >= board[0].size())
return;
if(board[x][y] != 'O')
return;
board[x][y] = '*';
if(x+2 < board.size())
dfs(x+1, y, board);
if(x-2 >= 0)
dfs(x-1, y, board);
if(y+2 < board[0].size())
dfs(x, y+1, board);
if(y-2 >= 0)
dfs(x, y-1, board);
}
void solve(vector<vector<char> >& board) {
if(board.size() == 0 || board[0].size() == 0)
return;
int n = board.size();
int m = board[0].size();
for(int j = 0;j < m;j++) {
if(board[0][j] == 'O')
dfs(0, j, board);
if(board[n-1][j] == 'O')
dfs(n-1, j, board);
}
for(int i = 0;i < n;i++) {
if(board[i][0] == 'O')
dfs(i, 0, board);
if(board[i][m-1] == 'O')
dfs(i, m-1, board);
}
for(int i = 0;i < n;i++) {
for(int j = 0;j < m;j++) {
if(board[i][j] != '*')
board[i][j] = 'X';
else
board[i][j] = 'O';
}
}
}
int main() {
char a[][4] = {{'X','X','X','X'},
{'X','O','O','X'},
{'X','X','O','X'},
{'X','O','X','X'}};
vector<vector<char> > board;
for(int i = 0;i < 4;i++) {
board.push_back(arrayToVector(a[i]));
}
solve(board);
print(board);
return 0;
}