Submission #315326

#	Time	Username	Problem	Language	Result	Execution time	Memory
315326		Kevin_Zhang_TW	Cat (info1cup19_cat)	C++17	Compilation error	0 ms	0 KiB

cat

#include<bits/stdc++.h>
#define pb emplace_back
#define AI(i) begin(i), end(i)
using namespace std;
using ll = long long;
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() {cerr << endl;}
template<class T1, class ...T2>
void kout (T1 v, T2 ...e) { cerr << v << ' ', kout(e...); }
template<class T>
void debug(T L, T R) { while (L != R) cerr << *L << " \n"[next(L)==R], ++L; }
#else
#define DE(...) 0
#define debug(...) 0
#endif
const int MAX_N = 300010;
int n;
vector<pair<int,int>> op;
// just the front half
void swap_sort(vector<int> p) {
}
bool valid(vector<int> p) {
	int cnt = 0, m = n / 2;
	for (int l = 0, r = n-1;l < r;++l, --r) {
		if ((p[l]>m) ^ (p[r]<=m))
			return false;
		if (p[l] > m)
			++cnt;
	}
	if (cnt & 1) 
		return false;
	vector<int> pos(n);
	for (int i = 0;i < n;++i)
		pos[ p[i] ] = i;
	auto sw = [&](int x, int y) {
		swap(p[x], p[y]), swap(pos[ p[x] ], pos[ p[y] ]);
	};
	auto do_op = [&](int x, int y) {
		int a = x, b = y, c = n - x - 1, d = n - y - 1;
		sw(a, b), sw(c, d);
	};
	for (int i = 0;i < m;++i) {
		while (i+1 != p[i]) 
			do_op(i, p[i]);
	}
	for (int i = 0;i < n;++i)
		if (p[i] != i+1)
			return false;
	return true;
}
// make p good enough so that I can do swap sort on it
void pair_good(vector<int> &p) {
}
bool solve() {
	cin >> n;
	vector<int> p(n);
	for (int &i : p)
		cin >> i;
	if (!valid(p))
		return false;
	pair_good(p);
	swap_sort(p);
	return true;
}
signed main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	int T;
	cin >> T;
	while (T--) {
		op.clear();
		if (!solve())
			cout << -1 << '\n';
		else {
			cout << op.size() << ' ' << op.size() << '\n';
			for (auto [a, b] : op)
				cout << a+1 << ' ' << b+1 << '\n';
		}
	}
}
#include<bits/stdc++.h>
#define pb emplace_back
#define AI(i) begin(i), end(i)
using namespace std;
using ll = long long;
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() {cerr << endl;}
template<class T1, class ...T2>
void kout (T1 v, T2 ...e) { cerr << v << ' ', kout(e...); }
template<class T>
void debug(T L, T R) { while (L != R) cerr << *L << " \n"[next(L)==R], ++L; }
#else
#define DE(...) 0
#define debug(...) 0
#endif
const int MAX_N = 300010;
int n;
vector<pair<int,int>> op;
// just the front half
void swap_sort(vector<int> p) {
}
bool valid(vector<int> p) {
	int cnt = 0, m = n / 2;
	for (int l = 0, r = n-1;l < r;++l, --r) {
		if ((p[l]>m) ^ (p[r]<=m))
			return false;
		if (p[l] > m)
			++cnt;
	}
	if (cnt & 1) 
		return false;
	vector<int> pos(n);
	for (int i = 0;i < n;++i)
		pos[ p[i] ] = i;
	auto sw = [&](int x, int y) {
		swap(p[x], p[y]), swap(pos[ p[x] ], pos[ p[y] ]);
	};
	auto do_op = [&](int x, int y) {
		int a = x, b = y, c = n - x - 1, d = n - y - 1;
		sw(a, b), sw(c, d);
	};
	for (int i = 0;i < m;++i) {
		while (i+1 != p[i]) 
			do_op(i, p[i]);
	}
	for (int i = 0;i < n;++i)
		if (p[i] != i+1)
			return false;
	return true;
}
// make p good enough so that I can do swap sort on it
void pair_good(vector<int> &p) {
}
bool solve() {
	cin >> n;
	vector<int> p(n);
	for (int &i : p)
		cin >> i;
	if (!valid(p))
		return false;
	pair_good(p);
	swap_sort(p);
	return true;
}
signed main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	int T;
	cin >> T;
	while (T--) {
		op.clear();
		if (!solve())
			cout << -1 << '\n';
		else {
			cout << op.size() << ' ' << op.size() << '\n';
			for (auto [a, b] : op)
				cout << a+1 << ' ' << b+1 << '\n';
		}
	}
}

Compilation message (stderr)

cat.cpp:97:11: error: redefinition of 'const int MAX_N'
   97 | const int MAX_N = 300010;
      |           ^~~~~
cat.cpp:17:11: note: 'const int MAX_N' previously defined here
   17 | const int MAX_N = 300010;
      |           ^~~~~
cat.cpp:98:5: error: redefinition of 'int n'
   98 | int n;
      |     ^
cat.cpp:18:5: note: 'int n' previously declared here
   18 | int n;
      |     ^
cat.cpp:99:23: error: redefinition of 'std::vector<std::pair<int, int> > op'
   99 | vector<pair<int,int>> op;
      |                       ^~
cat.cpp:19:23: note: 'std::vector<std::pair<int, int> > op' previously declared here
   19 | vector<pair<int,int>> op;
      |                       ^~
cat.cpp:101:6: error: redefinition of 'void swap_sort(std::vector<int>)'
  101 | void swap_sort(vector<int> p) {
      |      ^~~~~~~~~
cat.cpp:21:6: note: 'void swap_sort(std::vector<int>)' previously defined here
   21 | void swap_sort(vector<int> p) {
      |      ^~~~~~~~~
cat.cpp:103:6: error: redefinition of 'bool valid(std::vector<int>)'
  103 | bool valid(vector<int> p) {
      |      ^~~~~
cat.cpp:23:6: note: 'bool valid(std::vector<int>)' previously defined here
   23 | bool valid(vector<int> p) {
      |      ^~~~~
cat.cpp:133:6: error: redefinition of 'void pair_good(std::vector<int>&)'
  133 | void pair_good(vector<int> &p) {
      |      ^~~~~~~~~
cat.cpp:53:6: note: 'void pair_good(std::vector<int>&)' previously defined here
   53 | void pair_good(vector<int> &p) {
      |      ^~~~~~~~~
cat.cpp:135:6: error: redefinition of 'bool solve()'
  135 | bool solve() {
      |      ^~~~~
cat.cpp:55:6: note: 'bool solve()' previously defined here
   55 | bool solve() {
      |      ^~~~~
cat.cpp:146:8: error: redefinition of 'int main()'
  146 | signed main() {
      |        ^~~~
cat.cpp:66:8: note: 'int main()' previously defined here
   66 | signed main() {
      |        ^~~~