海岛个数问题LintCode

笔试编程题

[
[1, 1, 0, 0, 0],
[0, 1, 0, 0, 1],
[0, 0, 0, 1, 1],
[0, 0, 0, 0, 0],
[0, 0, 0, 0, 1]
]

void  DFS(vector<vector<bool>>& grid,int i,int j){
grid[i][j] = 0;
if(i>0&&grid[i-1][j])
DFS(grid,i-1,j);
if(j>0&&grid[i][j-1])
DFS(grid,i,j-1);
if(i<grid.size()-1 && grid[i+1][j])
DFS(grid,i+1,j);
if(j<grid[0].size()-1 && grid[i][j+1])
DFS(grid,i,j+1);
}
int numIslands(vector<vector<bool>>& grid) {
int count = 0;
for(int i = 0;i<grid.size();i++){
for(int j = 0;j<grid[0].size();j++){
if(grid[i][j]) {
DFS(grid,i,j);
count++;
}
}
}
return count;
}