Language: C++

#include <bits/stdc++.h>
#define REP(i, n) for(ll i = 0; i < (ll)n; i++)
#define FOR(i, a, b) for(ll i = (a); i < (ll)b; i++)
#define ALL(obj) (obj).begin(), (obj).end()
#define INF (1ll << 60)
#define sz(x) int(x.size())
using namespace std;
typedef long long ll;
using vl = vector<ll>;
using vvl = vector<vl>;
typedef double db;
typedef string str;
typedef pair<ll, ll> p;
constexpr int MOD = 1000000007;
using ll = long long;
template <class T> inline bool chmin(T &a, T b) {
    if(a > b) {
        a = b;
        return true;
    }
    return false;
}
template <class T> inline bool chmax(T &a, T b) {
    if(a < b) {
        a = b;
        return true;
    }
    return false;
}

void print(const std::vector<int> &v) {
    std::for_each(v.begin(), v.end(), [](int x) { std::cout << x << " "; });
    std::cout << std::endl;
}
// http://drken1215.hatenablog.com/entry/2019/03/24/110200
usign pint = pair<int, int>;
int main() {
    int N;
    cin >> N;
    vector<pint> res;
    int dame = N;
    if(N % 2 == 1) {
        //奇数なら
        dame--;
    }
    for(int i = 1; i < = N; i++) {
        for(int j = 1; j < = N; j++) {
            if(j <= i | j == dame) {
                continue;
            }
            res.push_back(pint(i, j));
        }
        dame--;
    }
    cout << res.size() << endl;
    for(auto p : res) {
        cout << p.first << " " << p.second << endl;
    }
}

Compiler output:
a.cc:36:1: error: 'usign' does not name a type
   36 | usign pint = pair<int, int>;
      | ^~~~~
a.cc: In function 'int main()':
a.cc:40:12: error: 'pint' was not declared in this scope; did you mean 'uint'?
   40 |     vector<pint> res;
      |            ^~~~
      |            uint
a.cc:40:16: error: template argument 1 is invalid
   40 |     vector<pint> res;
      |                ^
a.cc:40:16: error: template argument 2 is invalid
a.cc:46:24: error: expected primary-expression before '=' token
   46 |     for(int i = 1; i < = N; i++) {
      |                        ^
a.cc:47:28: error: expected primary-expression before '=' token
   47 |         for(int j = 1; j < = N; j++) {
      |                            ^
a.cc:51:17: error: request for member 'push_back' in 'res', which is of non-class type 'int'
   51 |             res.push_back(pint(i, j));
      |                 ^~~~~~~~~
a.cc:55:17: error: request for member 'size' in 'res', which is of non-class type 'int'
   55 |     cout << res.size() << endl;
      |                 ^~~~
a.cc:56:18: error: 'begin' was not declared in this scope
   56 |     for(auto p : res) {
      |                  ^~~
a.cc:56:18: note: suggested alternatives:
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166,
                 from a.cc:1:
/usr/include/c++/14/valarray:1238:5: note:   'std::begin'
 1238 |     begin(const valarray<_Tp>& __va) noexcept
      |     ^~~~~
In file included from /usr/include/c++/14/filesystem:53,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:200:
/usr/include/c++/14/bits/fs_dir.h:608:3: note:   'std::filesystem::__cxx11::begin'
  608 |   begin(recursive_directory_iterator __iter) noexcept
      |   ^~~~~
a.cc:56:18: error: 'end' was not declared in this scope
   56 |     for(auto p : res) {
      |                  ^~~
a.cc:56:18: note: suggested alternatives:
/usr/include/c++/14/valarray:1265:5: note:   'std::end'
 1265 |     end(const valarray<_Tp>& __va) noexcept
      |     ^~~
/usr/include/c++/14/bits/fs_dir.h:613:3: note:   'std::filesystem::__cxx11::end'
  613 |   end(recursive_directory_iterator) noexcept
      |   ^~~