update

README.md

@@ -11,3 +11,16 @@ algorithm_2024
 ### [OJ4980:拯救行动](http://noi.openjudge.cn/ch0205/4980/)
 
 #### 未考虑无答案（特殊情况）时输出
+
+#### 优先对联是从大到小排序，重载运算符时需反向或者std::greater
+```cpp
+struct Status{
+    Point now;
+    ll step;
+    bool operator<(const Status &that)const noexcept{
+        return this->step > that.step;
+    }
+};
+
+std::priority_queue<Status> q;
+```

src/oj4980/oj4980.cpp

@@ -5,7 +5,7 @@
 #include <queue>
 #include <bitset>
 
-typedef long long ll;
+using ll = long long;
 auto &is = std::cin;
 auto &os = std::cout;