cs: add «1769. Minimum Number of Operations to Move All Balls to Each Box»

URL:	https://leetcode.com/problems/minimum-number-of-operations-to-move-all-balls-to-each-box/
Signed-off-by: Matej Focko <me@mfocko.xyz>

cs/minimum-number-of-operations-to-move-all-balls-to-each-box.cs

@@ -0,0 +1,36 @@
+public class Solution {
+    private struct Direction {
+        int Balls;
+        int Moves;
+
+        public Direction() {
+            Balls = 0;
+            Moves = 0;
+        }
+
+        public int Update(char state) {
+            var moves = Moves;
+
+            Balls += state - '0';
+            Moves += Balls;
+
+            return moves;
+        }
+    }
+
+    public int[] MinOperations(string boxes) {
+        var answer = new int[boxes.Length];
+
+        var (left, right) = (new Direction(), new Direction());
+        for (var i = 0; i < boxes.Length; ++i) {
+            // from left side
+            answer[i] += left.Update(boxes[i]);
+
+            // from right side
+            var j = boxes.Length - i - 1;
+            answer[j] += right.Update(boxes[j]);
+        }
+
+        return answer;
+    }
+}