Submission #743150

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
743150	2023-05-17T08:23:17 Z	vjudge1	Lightning Rod (NOI18_lightningrod)	C++17	Compilation error	0 ms	0 KB

lightningrod

#include <iostream>
#include <unordered_map>
using namespace std;

inline void read(int &x)
{
    x = 0;
    char ch = getchar_unlocked();
    while (ch & 16)
    {
        x = (x << 3) + (x << 1) + (ch & 15);
        ch = getchar_unlocked();
    }
}

int main ()
{
    unordered_map<int,int> m;
    long long n, a, b, sum = 0;
    read(n);
    for(long long i = 0;i < n;++i)
    {
        read(a);
        read(b);
        if(ma[a] == 0)
        {
            ma[a] = 1;
            sum++;
        }
    }
    cout << sum;
}

Compilation message

lightningrod.cpp: In function 'int main()':
lightningrod.cpp:20:10: error: cannot bind non-const lvalue reference of type 'int&' to an rvalue of type 'int'
   20 |     read(n);
      |          ^
lightningrod.cpp:5:23: note:   initializing argument 1 of 'void read(int&)'
    5 | inline void read(int &x)
      |                  ~~~~~^
lightningrod.cpp:23:14: error: cannot bind non-const lvalue reference of type 'int&' to an rvalue of type 'int'
   23 |         read(a);
      |              ^
lightningrod.cpp:5:23: note:   initializing argument 1 of 'void read(int&)'
    5 | inline void read(int &x)
      |                  ~~~~~^
lightningrod.cpp:24:14: error: cannot bind non-const lvalue reference of type 'int&' to an rvalue of type 'int'
   24 |         read(b);
      |              ^
lightningrod.cpp:5:23: note:   initializing argument 1 of 'void read(int&)'
    5 | inline void read(int &x)
      |                  ~~~~~^
lightningrod.cpp:25:12: error: 'ma' was not declared in this scope; did you mean 'a'?
   25 |         if(ma[a] == 0)
      |            ^~
      |            a