all tasks

Task/Zig-zag-matrix/C-sharp/zig-zag-matrix.cs

@@ -0,0 +1,25 @@
+public static int[,] ZigZag(int n)
+{
+    int[,] result = new int[n, n];
+    int i = 0, j = 0;
+    int d = -1; // -1 for top-right move, +1 for bottom-left move
+    int start = 0, end = n * n - 1;
+    do
+    {
+        result[i, j] = start++;
+        result[n - i - 1, n - j - 1] = end--;
+
+        i += d; j -= d;
+        if (i < 0)
+        {
+            i++; d = -d; // top reached, reverse
+        }
+        else if (j < 0)
+        {
+            j++; d = -d; // left reached, reverse
+        }
+    } while (start < end);
+    if (start == end)
+        result[i, j] = start;
+    return result;
+}