leetcode

commit 6d780927f23d34e5bfddcde9392c5786d5861461
parent 687a03dd4ef45ec32e59e9b9d806e905f11d8c0e
Author: AndrewLockVI <andrewlaack1@gmail.com>
Date:   Tue,  9 May 2023 15:32:15 -0500

Completed spiral matrix problem using dart

Diffstat:
A
spiral-matrix/spiral-matrix.dart
 | 
49
+++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 49 insertions(+), 0 deletions(-)
diff --git a/spiral-matrix/spiral-matrix.dart b/spiral-matrix/spiral-matrix.dart
@@ -0,0 +1,49 @@
+//Given a matrix return the values contained within it
+//as a list in the order of a spiral.
+//Ex:
+// 1 2 3
+// 4 5 6
+// 7 8 9
+//Output:
+// [1,2,3,6,9,8,7,4,5]
+//To know when to end my code counts the number of spaces that I
+//have visited to see if I have gone to all of them. When I have 
+//the algorithm returns the list.
+//The time complexity of this code is O(n) where n is the h*w of the matrix
+//Time: 251ms Beats: 65.38%
+//Memory: 140.1MB Beats: 61.54%
+
+class Solution {
+  List<int> spiralOrder(List<List<int>> matrix) {
+      int margin_top = 0;
+      int margin_bottom = matrix.length;
+      int margin_right = matrix[0].length;
+      int margin_left = 0;
+      int rem = matrix.length * matrix[0].length;
+      List<int> return_vals = [];
+      while(rem > 0){
+          for(int i = margin_left ; i < margin_right && rem != 0  ; ++i){
+              return_vals.add(matrix[margin_top][i]);
+              rem -= 1;
+          }
+          margin_top += 1;
+          for(int i = margin_top ; i < margin_bottom && rem != 0  ; ++i){
+              return_vals.add(matrix[i][margin_right - 1]);
+              rem -= 1;
+          }
+          margin_right -= 1;
+          for(int i = margin_right - 1; i >= margin_left && rem != 0  ; --i){
+              return_vals.add(matrix[margin_bottom - 1][i]);
+              rem -= 1;
+          }
+          margin_bottom -= 1;
+          for(int i = margin_bottom - 1; i >= margin_top && rem != 0 ; --i){
+              return_vals.add(matrix[i][margin_left]);
+              rem -= 1;
+          }
+          margin_left += 1;
+      }
+      return return_vals;
+  }
+}
+