[Leetcode - Medium] Set Matrix Zeroes

suhwan2004/Set Matrix Zeroes.js

@@ -0,0 +1,56 @@
+/*
+23:02 ~ 23:43
+
+Time : O((m*n) * 4(m*n) => (m*n)^2) => 큐나 우선순위 큐 쓰면 m*n이 맞는데, 최악의 경우애는 4*(m*n) 만큼의 요소들이 들어갈 수 있고 하나가 shift되면 나머지가 다 땡겨져야되기 때문에 이렇게 됨
+Space : O(m*n)
+ALGO : BFS, for
+DS : array, hash set
+Constraints
+- m == matrix.length
+- n == matrix[0].length
+- 1 <= m, n <= 200
+- -2^31 <= matrix[i][j] <= 2^31 - 1
+Edge Case : X
+*/
+
+var setZeroes = function(matrix) {
+    const directions = [[0, 1], [1, 0], [-1, 0], [0, -1]];
+    let arr = [];
+    let visited = new Set();
+
+    for (let i = 0; i < matrix.length; i++) {
+        for (let j = 0; j < matrix[0].length; j++) {
+            if (matrix[i][j] === 0) {
+                for (let k = 0; k < directions.length; k++) {
+                    const newR = i + directions[k][0];
+                    const newC = j + directions[k][1];
+                    if (isValidRC(newR, newC, k)) {
+                        visited.add(`${newR},${newC},${k}`);
+                        arr.push([newR, newC, k]);
+                    }
+                }
+            }
+        }
+    }
+
+    while (arr.length > 0) {
+        const [curR, curC, curDirIdx] = arr.shift();
+        matrix[curR][curC] = 0;
+
+        const newR = curR + directions[curDirIdx][0];
+        const newC = curC + directions[curDirIdx][1];
+
+        if (isValidRC(newR, newC, curDirIdx)) {
+            visited.add(`${newR},${newC},${curDirIdx}`);
+            arr.push([newR, newC, curDirIdx]);
+        }
+    }
+
+
+    function isValidRC (r, c, dirIdx) {
+        return r >= 0 && r < matrix.length && c >= 0 && c < matrix[0].length && !visited.has(`${r},${c},${dirIdx}`)
+    }
+
+
+    return matrix;
+};