Create 0661-image-smoother.kt

Author: a93a

kotlin/0661-image-smoother.kt

@@ -0,0 +1,78 @@
+// O(n * m) time and O(n * m) space
+class Solution {
+    fun imageSmoother(img: Array<IntArray>): Array<IntArray> {
+        val n = img.size
+        val m = img[0].size
+        val dirs = arrayOf(
+            intArrayOf(0, 1),
+            intArrayOf(0, -1),
+            intArrayOf(1, 0),
+            intArrayOf(-1, 0),
+            intArrayOf(-1, -1),
+            intArrayOf(1, 1),
+            intArrayOf(-1, 1),
+            intArrayOf(1, -1)
+        )
+
+        val res = Array (n) { IntArray (m) }
+        for (i in 0 until n) {
+            for (j in 0 until m) {
+                var count = 1
+                var sum = img[i][j]
+                for (dir in dirs) {
+                    val i2 = i + dir[0]
+                    val j2 = j + dir[1]
+                    if (i2 in (0 until n) && j2 in (0 until m)) {
+                        count++
+                        sum += img[i2][j2]
+                    }
+                }
+                res[i][j] = sum / count
+            }
+        }
+
+        return res
+    }
+}
+
+// O(n * m) time and O(1) space
+class Solution {
+    fun imageSmoother(img: Array<IntArray>): Array<IntArray> {
+        val n = img.size
+        val m = img[0].size
+        val dirs = arrayOf(
+            intArrayOf(0, 1),
+            intArrayOf(0, -1),
+            intArrayOf(1, 0),
+            intArrayOf(-1, 0),
+            intArrayOf(-1, -1),
+            intArrayOf(1, 1),
+            intArrayOf(-1, 1),
+            intArrayOf(1, -1)
+        )
+
+        for (i in 0 until n) {
+            for (j in 0 until m) {
+                var count = 1
+                var sum = img[i][j]
+                for (dir in dirs) {
+                    val i2 = i + dir[0]
+                    val j2 = j + dir[1]
+                    if (i2 in (0 until n) && j2 in (0 until m)) {
+                        count++
+                        sum += img[i2][j2] and 0xFF
+                    }
+                }
+                img[i][j] = img[i][j] or ((sum / count) shl 8)
+            }
+        }
+
+        for (i in 0 until n) {
+            for (j in 0 until m) {
+                img[i][j] = img[i][j] shr 8
+            }
+        }
+
+        return img
+    }
+}