refactor(P3956.cpp): 移除魔法颜色处理逻辑中的冗余代码

简化bfs函数中处理魔法颜色的代码块，删除未使用的变量和重复逻辑

src/10/1/P3956.cpp

@@ -111,23 +111,7 @@ int bfs() {
             else if (nxtColor == -1 && !used) {
                 int magicCost = 2;
                 for (int magicColor = 0; magicColor <= 1; magicColor++) {
-                    int addCost = 0;
+                    
-                    if (lastColor != magicColor) {
-                        addCost = 1;
-                    }
-                    int totalCost = cost + addCost + magicCost;
-                    int newLastColor = magicColor;
-                    bool newused = true;  
-                    if (totalCost < dist[nx][ny][newused][newLastColor]) {
-                        dist[nx][ny][newused][newLastColor] = totalCost;
-                        Node nxt;
-                        nxt.x = nx;
-                        nxt.y = ny;
-                        nxt.cost = totalCost;
-                        nxt.lastColor = newLastColor;
-                        nxt.used = newused;
-                        pq.push(nxt);
-                    }
                 }
             }
         }

src/10/1/P4162.cpp

@@ -0,0 +1,3 @@
+int main(){
+    
+}