- 技术博客
- 岛屿数量
class Solution {
public int numIslands(char[][] grid
) {
int islandNum
= 0;
for(int i
= 0; i
< grid
.length
; i
++){
for(int j
= 0; j
< grid
[0].length
; j
++){
if(grid
[i
][j
] == '1'){
infect(grid
, i
, j
);
islandNum
++;
}
}
}
return islandNum
;
}
public void infect(char[][] grid
, int i
, int j
){
if(i
< 0 || i
>= grid
.length
||
j
< 0 || j
>= grid
[0].length
|| grid
[i
][j
] != '1'){
return;
}
grid
[i
][j
] = '2';
infect(grid
, i
+ 1, j
);
infect(grid
, i
- 1, j
);
infect(grid
, i
, j
+ 1);
infect(grid
, i
, j
- 1);
}
}
