update 200 java, progress

yennanliu · May 20, 2024 · 5553ec7 · 5553ec7
1 parent cdd3b2e
commit 5553ec7
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Showing 4 changed files with 128 additions and 12 deletions.
diff --git a/data/progress.txt b/data/progress.txt
@@ -1,4 +1,4 @@
-20240520: 73
+20240520: 73,200
 20240519: 207,79,206,213,198
 20240518: 212(todo),211,338,208(again)
 20240517: 347,253(todo),91(todo),217

diff --git a/data/to_review.txt b/data/to_review.txt
@@ -1,4 +1,4 @@
-2024-07-14 -> ['73']
+2024-07-14 -> ['73,200']
 2024-07-13 -> ['207,79,206,213,198']
 2024-07-12 -> ['212(todo),211,338,208(again)']
 2024-07-11 -> ['347,253(todo),91(todo),217']
@@ -9,7 +9,7 @@
 2024-07-06 -> ['371']
 2024-07-05 -> ['121,252']
 2024-07-04 -> ['125']
-2024-06-23 -> ['73']
+2024-06-23 -> ['73,200']
 2024-06-22 -> ['207,79,206,213,198']
 2024-06-21 -> ['212(todo),211,338,208(again)']
 2024-06-20 -> ['347,253(todo),91(todo),217']
@@ -20,27 +20,27 @@
 2024-06-15 -> ['371']
 2024-06-14 -> ['121,252']
 2024-06-13 -> ['125']
-2024-06-10 -> ['73']
+2024-06-10 -> ['73,200']
 2024-06-09 -> ['207,79,206,213,198']
 2024-06-08 -> ['212(todo),211,338,208(again)']
 2024-06-07 -> ['347,253(todo),91(todo),217']
 2024-06-06 -> ['226,98,253(todo)']
 2024-06-05 -> ['104,230,102,100']
 2024-06-04 -> ['105,106']
 2024-06-03 -> ['242,235']
-2024-06-02 -> ['73', '371']
+2024-06-02 -> ['73,200', '371']
 2024-06-01 -> ['207,79,206,213,198', '121,252']
 2024-05-31 -> ['212(todo),211,338,208(again)', '125']
 2024-05-30 -> ['347,253(todo),91(todo),217']
 2024-05-29 -> ['226,98,253(todo)']
-2024-05-28 -> ['73', '104,230,102,100']
+2024-05-28 -> ['73,200', '104,230,102,100']
 2024-05-27 -> ['207,79,206,213,198', '105,106']
 2024-05-26 -> ['212(todo),211,338,208(again)', '242,235']
-2024-05-25 -> ['73', '347,253(todo),91(todo),217', '371']
+2024-05-25 -> ['73,200', '347,253(todo),91(todo),217', '371']
 2024-05-24 -> ['207,79,206,213,198', '226,98,253(todo)', '121,252']
-2024-05-23 -> ['73', '212(todo),211,338,208(again)', '104,230,102,100', '125']
-2024-05-22 -> ['73', '207,79,206,213,198', '347,253(todo),91(todo),217', '105,106']
-2024-05-21 -> ['73', '207,79,206,213,198', '212(todo),211,338,208(again)', '226,98,253(todo)', '242,235']
+2024-05-23 -> ['73,200', '212(todo),211,338,208(again)', '104,230,102,100', '125']
+2024-05-22 -> ['73,200', '207,79,206,213,198', '347,253(todo),91(todo),217', '105,106']
+2024-05-21 -> ['73,200', '207,79,206,213,198', '212(todo),211,338,208(again)', '226,98,253(todo)', '242,235']
 2024-05-20 -> ['207,79,206,213,198', '212(todo),211,338,208(again)', '347,253(todo),91(todo),217', '104,230,102,100', '371']
 2024-05-19 -> ['212(todo),211,338,208(again)', '347,253(todo),91(todo),217', '226,98,253(todo)', '105,106', '121,252']
 2024-05-18 -> ['347,253(todo),91(todo),217', '226,98,253(todo)', '104,230,102,100', '242,235', '125']

diff --git a/leetcode_java/src/main/java/LeetCodeJava/DFS/NumberOfIslands.java b/leetcode_java/src/main/java/LeetCodeJava/DFS/NumberOfIslands.java
@@ -61,12 +61,67 @@ private boolean _is_island(char[][] grid, int x, int y, boolean[][] seen){
         return true;
     }
 
-    // V0
+    // V0'
+    // IDEA: DFS (with looping)
+    public int numIslands_0(char[][] grid) {
+        if (grid == null || grid.length == 0 || grid[0].length == 0) {
+            return 0;
+        }
+
+        int l = grid.length;
+        int w = grid[0].length;
+        int res = 0;
+
+        for (int i = 0; i < l; i++) {
+            for (int j = 0; j < w; j++) {
+                /**
+                 *  NOTE !!!
+                 *
+                 *   if grid[i][j] == '1', no need to collect the coordinate (x,y),
+                 *   -> just add res with 1,
+                 *   -> and call dfs function
+                 */
+                if (grid[i][j] == '1') {
+                    res += 1;
+                    dfs(grid, i, j);
+                }
+            }
+        }
+
+        return res;
+    }
+
+    /** NOTE !!!
+     *
+     *   NO NEED to return boolean val on this helper function (dfs),
+     *   since we mark point as "visited" in place with traversing,
+     *   so no response (void) is OK
+     */
+    private void dfs(char[][] grid, int y, int x) {
+
+        int l = grid.length;
+        int w = grid[0].length;
+
+        if (y < 0 || y >= l || x < 0 || x >= w || grid[y][x] != '1') {
+            return;
+        }
+
+        grid[y][x] = '#'; // Mark the cell as visited
+
+        int[][] dirs = new int[][]{{0, 1}, {0, -1}, {1, 0}, {-1, 0}};
+        for (int[] dir : dirs) {
+            int newY = y + dir[0];
+            int newX = x + dir[1];
+            dfs(grid, newY, newX);
+        }
+    }
+
+    // V0'
     // IDEA : DFS (with looping) (modified by GPT)
     int num_island_2 = 0;
     boolean[][] _seen_2;
 
-    public int numIslands_0(char[][] grid) {
+    public int numIslands_0_1(char[][] grid) {
         if (grid.length == 1 && grid[0].length == 1) {
             return grid[0][0] == '1' ? 1 : 0;
         }

diff --git a/leetcode_java/src/main/java/dev/workspace3.java b/leetcode_java/src/main/java/dev/workspace3.java
@@ -1126,4 +1126,65 @@ public void setZeroes(int[][] matrix) {
         return;
     }
 
+    // LC 200
+    // dfs
+    public int numIslands(char[][] grid) {
+
+        if (grid.length == 0 && grid[0].length == 0){
+            return 0;
+        }
+
+        int l = grid.length;
+        int w = grid[0].length;
+
+        // get "1"
+        List<int[]> collected = new ArrayList<>();
+        for (int i = 0; i < w; i++){
+            for (int j = 0; j < l; j++){
+                if (grid[j][i] == '1'){
+                    collected.add(new int[]{i,j});
+                }
+            }
+        }
+
+        System.out.println("--> collected = ");
+        for (int[] point : collected){
+            System.out.println("x = " + point[0] + " y = " + point[1]);
+        }
+
+        int res = 0;
+        // dfs
+        for (int[] point : collected){
+            if (this.dfs_help(grid, point[0], point[1])){
+                res += 1;
+            }
+        }
+
+        return res;
+    }
+
+    public boolean dfs_help(char[][] grid, int x, int y){
+
+        int l = grid.length;
+        int w = grid[0].length;
+
+        // dirs
+        int[][] dirs = new int[][]{{0,1}, {0,-1}, {1,0}, {-1,0} };
+
+        if (x < 0 || x >= w || y < 0 || y >= l || grid[y][x] != '1'){
+            return false;
+        }
+
+        for (int[] dir: dirs){
+
+            int x_ = x + dir[0];
+            int y_ = y + dir[1];
+
+            // mark as visited
+            grid[y_][x_] = '#'; // NOTE !!! we setup char via single quote ('#')
+            this.dfs_help(grid, x_, y_);
+        }
+        return true;
+    }
+
 }