update

CMakeLists.txt

@@ -32,3 +32,5 @@ add_executable(P1003 ${CMAKE_CURRENT_LIST_DIR}/P1003/P1003.cpp)
 add_executable(P1311 ${CMAKE_CURRENT_LIST_DIR}/P1311/P1311.cpp)
 
 add_executable(P4017 ${CMAKE_CURRENT_LIST_DIR}/P4017/P4017.cpp)
+
+add_executable(P2782 ${CMAKE_CURRENT_LIST_DIR}/P2782/P2782.cpp)

P2782/P2782.cpp

@@ -0,0 +1,59 @@
+#include <iostream>
+#include <algorithm>
+
+using std::cin,std::cout,std::sort,std::max;
+
+constexpr int MAX_N {(int)2e5+5};
+struct City{
+    int a,b;
+    bool operator<(const City &that)const noexcept{
+        return this->a<that.a;
+    }
+} city[MAX_N];
+int n, len[MAX_N],ans;
+
+template<class T>
+class ReadNumber{
+    char c;
+    T w,n;
+public:
+    ReadNumber& operator>>(T &num)noexcept{
+        c=(char)0,w=1,n=0;
+        while(!isdigit(c)){
+            // if constexpr(!std::is_same_v<ull, T>){
+            //     if(c=='-')w=-1;
+            // }
+            c = getchar();
+        }
+        while(isdigit(c)){
+            n = n*10 + (c-'0');
+            c = getchar();
+        }
+        num = w*n;
+        return *this;
+    }
+};
+
+ReadNumber<int> readint;
+#define cin readint
+
+int main(){
+    cin>>n;
+    for(int i=0;i<n;i++){
+        cin>>city[i].a>>city[i].b;
+        len[i]=1;
+    }
+    sort(city,city+n);
+    for(int i=0;i<n;i++){
+        for(int j=i-1;j>=0;j--){
+            if(city[j].b<city[i].b && len[i]<len[j]+1){
+                len[i]=len[j]+1;
+            }
+        }
+    }
+    for(int i=0;i<n;i++){
+        // cout<<"i:"<<i<<"  "<<"len:"<<len[i]<<'\n';
+        ans = max(ans,len[i]);
+    }
+    cout<<ans<<'\n';
+}