Merge pull request #1246 from harshitcompcode/patch-1

Create distance_of_nearest_zero.js

Author: akgmage

Dynamic Programming/distance_of_nearest_zero.js

@@ -0,0 +1,50 @@
+Example:
+Input: mat = [[0,0,0],[0,1,0],[0,0,0]]
+Output: [[0,0,0],[0,1,0],[0,0,0]]
+
+It can be solved using a Breadth First Search Algorithm(BFS)
+
+function updateMatrix(mat) {
+  const m = mat.length;
+  const n = mat[0].length;
+  const queue = [];
+  
+  // Initialize distance matrix with maximum possible values
+  const dist = new Array(m).fill().map(() => new Array(n).fill(Number.MAX_VALUE));
+  
+  // Initialize the queue with all cells containing 0
+  for (let i = 0; i < m; i++) {
+    for (let j = 0; j < n; j++) {
+      if (mat[i][j] === 0) {
+        dist[i][j] = 0;
+        queue.push([i, j]);
+      }
+    }
+  }
+  
+  // Perform a BFS starting from the cells containing 0
+  while (queue.length > 0) {
+    const [i, j] = queue.shift();
+    
+    // Check the neighbors of the current cell
+    const neighbors = [[i - 1, j], [i + 1, j], [i, j - 1], [i, j + 1]];
+    for (const [ni, nj] of neighbors) {
+      // Check if the neighbor is within bounds
+      if (ni >= 0 && ni < m && nj >= 0 && nj < n) {
+        // If the distance to the neighbor can be updated
+        if (dist[ni][nj] > dist[i][j] + 1) {
+          dist[ni][nj] = dist[i][j] + 1;
+          queue.push([ni, nj]);
+        }
+      }
+    }
+  }
+  
+  return dist;
+}
+
+
+The updateMatrix function takes a binary matrix mat as input and returns a matrix dist with the distance of the nearest 0 for each cell.
+The algorithm first initializes the dist matrix with maximum possible values and adds all cells containing 0 to a queue. 
+Then, it performs a BFS starting from the cells in the queue and updates the distances of the neighboring cells if they can be improved. 
+Finally, it returns the dist matrix with the updated distances.