oj.uz

Submission #315341

# Submission time Handle Problem Language Result Execution time Memory
315341 2020-10-22T14:27:02 Z Kevin_Zhang_TW Cat (info1cup19_cat) C++17
100 / 100
 670 ms 13580 KB 
#include<bits/stdc++.h>
#define pb emplace_back
#define AI(i) begin(i), end(i)
using namespace std;
using ll = long long;
//#undef KEV
#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) {
	vector<int> pos(n+1);
	int m = n/2;
	for (int i = 0; i < n;++i)
		pos[ p[i] ] = i;
	auto sw = [&](int x, int y) {
		op.pb(x, y);
		swap(p[x], p[y]), swap(pos[p[x]], pos[p[y]]);
	};
	for (int i = 0;i < m;++i) {
		while (i+1 != p[i]) 
			sw(i, pos[i+1]);
	}
}
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;
	DE(cnt);
	vector<int> ln, rn;
	for (int i = 0;i < m;++i)
		if (p[i] > m)
			ln.pb(i);
	for (int i = n-1;i >= m;--i)
		if (p[i] <= m)
			rn.pb(i);

	assert(cnt == ln.size() && cnt == rn.size());
	vector<int> pos(n+1);
	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 < cnt;i += 2)
		do_op(ln[i], rn[i+1]);

	for (int i = 0;i < m;++i) {
		while (i+1 != p[i]) {
			do_op(i, pos[i+1]);
		}
	}
	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
vector<int> pair_good(vector<int> p) {
	vector<int> notp;
	vector<int> pos(n+1);
	vector<int> goodp(p);
	debug(AI(p));
	auto put = [&](int id) {
		DE(id);
		notp.pb(id);
	};
	auto sw = [&](int a, int b) {
		swap(p[a], p[b]), swap(pos[ p[a] ], pos[ p[b] ]);
	};
	auto do_op = [&](int x, int y) {
		DE(x, y);
		int a = x, b = y, c = n - a - 1, d = n - b - 1;
		swap( goodp[a], goodp[b] );
		swap( goodp[c], goodp[d] );
		op.pb(a, b);
	};
		
	auto pop = [&]() {
		while (notp.size() > 1) {
			int a = notp.back(); notp.pop_back();
			int b = notp.back(); notp.pop_back();
			do_op(a, n-b-1);
		}
	};
	int m = n / 2;
	vector<bool> ch(n), vis(n);
	int cnt = 0;
	for (int i = 0;i < m;++i)
		if (p[i] > m)
			swap(p[i], p[n-i-1]), ch[i] = true, ++cnt;


	for (int i = 0;i < m;++i) 
		pos[p[i]] = i;

	DE(cnt);
	debug(AI(p));
	for (int i = 0;i < m;++i) {
		if (vis[i]) continue;
		vis[i] = true;
		if (ch[i])
			put(i);
			
		while (i+1 != p[i]) {
			int x = p[i]-1;
			if (ch[x])
				put(x);

			vis[x] = true;
			sw(i, x);
		}
		pop();
	}
	assert(notp.empty());
	cerr << "GoodP\n";
	debug(AI(goodp));
	return goodp;
}
bool solve() {
	cin >> n;
	vector<int> p(n);
	for (int &i : p)
		cin >> i;
	debug(AI(p));
	if (!valid(p))
		return false;
	p = 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

cat.cpp: In function 'bool valid(std::vector<int>)':
cat.cpp:15:17: warning: statement has no effect [-Wunused-value]
   15 | #define DE(...) 0
      |                 ^
cat.cpp:46:2: note: in expansion of macro 'DE'
   46 |  DE(cnt);
      |  ^~
In file included from /usr/include/c++/9/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:33,
                 from cat.cpp:1:
cat.cpp:55:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |  assert(cnt == ln.size() && cnt == rn.size());
      |         ~~~~^~~~~~~~~~~~
cat.cpp:55:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |  assert(cnt == ln.size() && cnt == rn.size());
      |                             ~~~~^~~~~~~~~~~~
cat.cpp: In function 'std::vector<int> pair_good(std::vector<int>)':
cat.cpp:16:20: warning: statement has no effect [-Wunused-value]
   16 | #define debug(...) 0
      |                    ^
cat.cpp:84:2: note: in expansion of macro 'debug'
   84 |  debug(AI(p));
      |  ^~~~~
cat.cpp: In lambda function:
cat.cpp:15:17: warning: statement has no effect [-Wunused-value]
   15 | #define DE(...) 0
      |                 ^
cat.cpp:86:3: note: in expansion of macro 'DE'
   86 |   DE(id);
      |   ^~
cat.cpp: In lambda function:
cat.cpp:15:17: warning: statement has no effect [-Wunused-value]
   15 | #define DE(...) 0
      |                 ^
cat.cpp:93:3: note: in expansion of macro 'DE'
   93 |   DE(x, y);
      |   ^~
cat.cpp: In function 'std::vector<int> pair_good(std::vector<int>)':
cat.cpp:15:17: warning: statement has no effect [-Wunused-value]
   15 | #define DE(...) 0
      |                 ^
cat.cpp:118:2: note: in expansion of macro 'DE'
  118 |  DE(cnt);
      |  ^~
cat.cpp:16:20: warning: statement has no effect [-Wunused-value]
   16 | #define debug(...) 0
      |                    ^
cat.cpp:119:2: note: in expansion of macro 'debug'
  119 |  debug(AI(p));
      |  ^~~~~
cat.cpp:16:20: warning: statement has no effect [-Wunused-value]
   16 | #define debug(...) 0
      |                    ^
cat.cpp:138:2: note: in expansion of macro 'debug'
  138 |  debug(AI(goodp));
      |  ^~~~~
cat.cpp: In function 'bool solve()':
cat.cpp:16:20: warning: statement has no effect [-Wunused-value]
   16 | #define debug(...) 0
      |                    ^
cat.cpp:146:2: note: in expansion of macro 'debug'
  146 |  debug(AI(p));
      |  ^~~~~

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 384 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 47 ms 632 KB Output is correct
2 Correct 44 ms 632 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 384 KB Output is correct
2 Correct 47 ms 632 KB Output is correct
3 Correct 44 ms 632 KB Output is correct
4 Correct 51 ms 668 KB Output is correct
5 Correct 19 ms 512 KB Output is correct
6 Correct 17 ms 512 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 47 ms 632 KB Output is correct
2 Correct 44 ms 632 KB Output is correct
3 Correct 565 ms 12720 KB Output is correct
4 Correct 544 ms 11572 KB Output is correct
5 Correct 621 ms 13580 KB Output is correct

Subtask #5
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 384 KB Output is correct
2 Correct 47 ms 632 KB Output is correct
3 Correct 44 ms 632 KB Output is correct
4 Correct 51 ms 668 KB Output is correct
5 Correct 19 ms 512 KB Output is correct
6 Correct 17 ms 512 KB Output is correct
7 Correct 565 ms 12720 KB Output is correct
8 Correct 544 ms 11572 KB Output is correct
9 Correct 621 ms 13580 KB Output is correct
10 Correct 629 ms 11500 KB Output is correct
11 Correct 557 ms 10116 KB Output is correct
12 Correct 565 ms 11596 KB Output is correct
13 Correct 670 ms 13376 KB Output is correct
14 Correct 560 ms 10964 KB Output is correct