cs: add «649. Dota2 Senate»

Signed-off-by: Matej Focko <me@mfocko.xyz>

cs/dota2-senate.cs

@@ -0,0 +1,27 @@
+public class Solution {
+    public string PredictPartyVictory(string senate) {
+        var radiant = new Queue<int>();
+        var dire = new Queue<int>();
+
+        for (var i = 0; i < senate.Length; ++i) {
+            (senate[i] == 'R' ? radiant : dire).Enqueue(i);
+        }
+
+        while (radiant.Count > 0 && dire.Count > 0) {
+            var r = radiant.Dequeue();
+            var d = dire.Dequeue();
+
+            if (r < d) {
+                radiant.Enqueue(senate.Length + r);
+            } else {
+                dire.Enqueue(senate.Length + d);
+            }
+        }
+
+        if (radiant.Count > 0) {
+            return "Radiant";
+        }
+
+        return "Dire";
+    }
+}