diff options
Diffstat (limited to 'number_islands.cpp')
-rw-r--r-- | number_islands.cpp | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/number_islands.cpp b/number_islands.cpp new file mode 100644 index 0000000..96b8e0b --- /dev/null +++ b/number_islands.cpp @@ -0,0 +1,30 @@ +#include "leetcode.h" + +class Solution { +public: + int numIslands(vector<vector<char>> &grid) { + int islands = 0; + for (int i = 0; i < grid.size(); i++) { + for (int j = 0; j < grid[0].size(); j++) { + if (grid[i][j] == '1') { + dfs(grid, i, j); + ++islands; + } + } + } + return islands; + } + +private: + void dfs(vector<vector<char>> &grid, int i, int j) { + if (i < 0 || i >= grid.size() || j < 0 || j >= grid[0].size()) + return; + if (grid[i][j] == '2' || grid[i][j] == '0') + return; + grid[i][j] = '2'; + dfs(grid, i + 1, j); + dfs(grid, i, j + 1); + dfs(grid, i - 1, j); + dfs(grid, i, j + 1); + } +}; |