0885

0801-0900/0885_spiral_matrix_iii.rb

@@ -0,0 +1,49 @@
+# @param {Integer} rows
+# @param {Integer} cols
+# @param {Integer} r_start
+# @param {Integer} c_start
+# @return {Integer[][]}
+def spiral_matrix_iii(rows, cols, r_start, c_start)
+ path = []
+ size = rows * cols
+ r = r_start
+ c = c_start
+ d = 0
+ loop do
+ # bot-left -> up-left
+ (0..d).each { |y|
+ _r = r - y
+ path.push([_r, c]) if c >= 0 && c < cols && _r >= 0 && _r < rows 
+ }
+ r -= d
+
+ d += 1
+
+ # up-left -> up-right
+ (1..d).each { |x|
+ _c = c + x
+ path.push([r, _c]) if _c >= 0 && _c < cols && r >= 0 && r < rows
+ }
+ c += d
+
+ # up-right -> bot-right
+ (1..d).each { |y|
+ _r = r + y
+ path.push([_r, c]) if c >= 0 && c < cols && _r >= 0 && _r < rows
+ }
+ r += d
+
+ # bot-right -> bot-left
+ (1..d).each { |x|
+ _c = c - x
+ path.push([r, _c]) if _c >= 0 && _c < cols && r >= 0 && r < rows
+ }
+ c -= d
+
+ d += 1
+ c -= 1
+ break if path.size >= size
+ end
+
+ path
+end