leetcode

commit f4e383686eaff5d6898e2908cc1180a0bdda450e
parent e16405943e9eda2fc55689093c666c056249b664
Author: AndrewLockVI <andrewlaack1@gmail.com>
Date:   Tue,  9 May 2023 20:38:18 -0500

Completed spiral matrix ii using dart

Diffstat:
A
spiral-matrix-ii/spiral-matrix-ii.dart
 | 
59
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 59 insertions(+), 0 deletions(-)
diff --git a/spiral-matrix-ii/spiral-matrix-ii.dart b/spiral-matrix-ii/spiral-matrix-ii.dart
@@ -0,0 +1,59 @@
+//Take a number as the input and return a matrix
+//of the same width and height as the number where the 
+//values within it are ordered in a spiral formation.
+//Ex.
+//Input:
+// 3
+// 1 2 3
+// 8 9 4
+// 7 6 5
+//The time complexity of this code is O(n^2) where n is the input number.
+//Time: 260ms Beats: 75%
+//Memory: 140.6MB Beats: 75%
+
+class Solution {
+  List<List<int>> generateMatrix(int n) {
+      int placed = 1;
+      List<List<int>> spiral = [];
+      int top_margin = 0;
+      int bottom_margin = n;
+      int left_margin = 0;
+      int right_margin = n;
+      for(int i = 0 ; i < n ; ++i){
+          spiral.add([]);
+          for(int x = 0 ; x < n ; ++x){
+              spiral[spiral.length - 1].add(0);
+          }
+      }
+      while(placed < n*n + 1){
+          for(int i = left_margin ; i < right_margin; ++i){
+              spiral[top_margin][i] = placed;
+              placed += 1;
+          }
+          top_margin += 1;
+
+          for(int i = top_margin ; i < bottom_margin ; ++i){
+              spiral[i][right_margin - 1] = placed;
+              placed += 1;
+
+          }
+          right_margin -= 1;
+          
+          for(int i = right_margin - 1 ; i >= left_margin ; --i){
+              spiral[bottom_margin - 1][i] = placed;
+              placed += 1;
+
+          }
+          bottom_margin -= 1;
+
+          for(int i = bottom_margin - 1; i >= top_margin ; --i){
+              spiral[i][left_margin] = placed;
+              placed += 1;
+
+          }
+          left_margin += 1;
+      }
+
+      return spiral;
+  }
+}