oj.uz

답안 #160480

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
160480 2019-10-27T15:09:53 Z Benq Cat (info1cup19_cat) C++14
100 / 100
 617 ms 12660 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>
 
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;
 
typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
 
typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;
 
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
 
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define F0R(i, a) for (int i = 0; i < (a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= (a); i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
#define trav(a, x) for (auto& a : x)
 
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
 
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rsz resize
 
const int MOD = 1000000007; // 998244353
const ll INF = 1e18;
const int MX = 200005;
const ld PI = 4*atan((ld)1);
 
template<class T> void ckmin(T &a, T b) { a = min(a, b); }
template<class T> void ckmax(T &a, T b) { a = max(a, b); }
 
namespace input {
    template<class T> void re(complex<T>& x);
    template<class T1, class T2> void re(pair<T1,T2>& p);
    template<class T> void re(vector<T>& a);
    template<class T, size_t SZ> void re(array<T,SZ>& a);
 
    template<class T> void re(T& x) { cin >> x; }
    void re(double& x) { string t; re(t); x = stod(t); }
    void re(ld& x) { string t; re(t); x = stold(t); }
    template<class Arg, class... Args> void re(Arg& first, Args&... rest) { 
        re(first); re(rest...); 
    }
 
    template<class T> void re(complex<T>& x) { T a,b; re(a,b); x = cd(a,b); }
    template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.f,p.s); }
    template<class T> void re(vector<T>& a) { F0R(i,sz(a)) re(a[i]); }
    template<class T, size_t SZ> void re(array<T,SZ>& a) { F0R(i,SZ) re(a[i]); }
}
 
using namespace input;
 
namespace output {
    template<class T1, class T2> void pr(const pair<T1,T2>& x);
    template<class T, size_t SZ> void pr(const array<T,SZ>& x);
    template<class T> void pr(const vector<T>& x);
    template<class T> void pr(const set<T>& x);
    template<class T1, class T2> void pr(const map<T1,T2>& x);
 
    template<class T> void pr(const T& x) { cout << x; }
    template<class Arg, class... Args> void pr(const Arg& first, const Args&... rest) { 
        pr(first); pr(rest...); 
    }
 
    template<class T1, class T2> void pr(const pair<T1,T2>& x) { 
        pr("{",x.f,", ",x.s,"}"); 
    }
    template<class T> void prContain(const T& x) {
        pr("{");
        bool fst = 1; for (const auto& a: x) pr(!fst?", ":"",a), fst = 0; // const needed for vector<bool>
        pr("}");
    }
    template<class T, size_t SZ> void pr(const array<T,SZ>& x) { prContain(x); }
    template<class T> void pr(const vector<T>& x) { prContain(x); }
    template<class T> void pr(const set<T>& x) { prContain(x); }
    template<class T1, class T2> void pr(const map<T1,T2>& x) { prContain(x); }
    
    void ps() { pr("\n"); }
    template<class Arg> void ps(const Arg& first) { 
        pr(first); ps(); // no space at end of line
    }
    template<class Arg, class... Args> void ps(const Arg& first, const Args&... rest) { 
        pr(first," "); ps(rest...); // print w/ spaces
    }
}
 
using namespace output;
 
namespace io {
    void setIn(string s) { freopen(s.c_str(),"r",stdin); }
    void setOut(string s) { freopen(s.c_str(),"w",stdout); }
    void setIO(string s = "") {
        ios_base::sync_with_stdio(0); cin.tie(0); // fast I/O
        if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
    }
}
 
using namespace io;
 
template<class T> T invGeneral(T a, T b) {
    a %= b; if (a == 0) return b == 1 ? 0 : -1;
    T x = invGeneral(b,a); 
    return x == -1 ? -1 : ((1-(ll)b*x)/a+b)%b;
}
 
template<class T> struct modular {
    T val; 
    explicit operator T() const { return val; }
    modular() { val = 0; }
    modular(const ll& v) { 
        val = (-MOD <= v && v <= MOD) ? v : v % MOD;
        if (val < 0) val += MOD;
    }
    
    friend ostream& operator<<(ostream& os, const modular& a) { return os << a.val; }
    friend bool operator==(const modular& a, const modular& b) { return a.val == b.val; }
    friend bool operator!=(const modular& a, const modular& b) { return !(a == b); }
    friend bool operator<(const modular& a, const modular& b) { return a.val < b.val; }
 
    modular operator-() const { return modular(-val); }
    modular& operator+=(const modular& m) { if ((val += m.val) >= MOD) val -= MOD; return *this; }
    modular& operator-=(const modular& m) { if ((val -= m.val) < 0) val += MOD; return *this; }
    modular& operator*=(const modular& m) { val = (ll)val*m.val%MOD; return *this; }
    friend modular pow(modular a, ll p) {
        modular ans = 1; for (; p; p /= 2, a *= a) if (p&1) ans *= a;
        return ans;
    }
    friend modular inv(const modular& a) { 
        auto i = invGeneral(a.val,MOD); assert(i != -1);
        return i;
    } // equivalent to return exp(b,MOD-2) if MOD is prime
    modular& operator/=(const modular& m) { return (*this) *= inv(m); }
    
    friend modular operator+(modular a, const modular& b) { return a += b; }
    friend modular operator-(modular a, const modular& b) { return a -= b; }
    friend modular operator*(modular a, const modular& b) { return a *= b; }
    
    friend modular operator/(modular a, const modular& b) { return a /= b; }
};
 
typedef modular<int> mi;
typedef pair<mi,mi> pmi;
typedef vector<mi> vmi;
typedef vector<pmi> vpmi;
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
 
vpi v;
int N;
vpi ans;
 
void mov(int a, int b, int c) {
	if (c == 0) {
		ans.pb({a+1,b+1});
		swap(v[a],v[b]);
	} else {
		ans.pb({a+1,N-b});
		swap(v[a],v[b]);
		v[a].s ^= 1, v[b].s ^= 1;
	}
}
 
int tri(vpi a) {
	vector<bool> vis(sz(a));
	int res = 0;
	F0R(i,sz(a)) if (!vis[i]) {
		int rev = 0, cnt = 0;
		int cur = i;
		while (!vis[cur]) {
			cnt ++;
			vis[cur] = 1; rev += a[cur].s;
			cur = a[cur].f;
		}
		res += cnt-1+(rev&1);
	}
	return res;
}

void solve() {
	v.clear(); ans.clear();
	re(N); vi a(N); re(a); vi ori = a;
	trav(t,a) t --;
	F0R(i,N/2) if (a[i]+a[N-1-i] != N-1) {
		ps(-1);
		return;
	}
	F0R(i,N/2) v.pb({min(a[i],a[N-1-i]),a[i] > a[N-1-i]});
	vpi vv = v;
	int tmp = tri(v);
	F0R(i,N/2) while (v[i].f != i) {
		if (v[i].s) mov(i,v[i].f,1);
		else mov(i,v[i].f,0);
	}
	vi bad;
	F0R(i,sz(v)) if (v[i].s) bad.pb(i);
	if (sz(bad)&1) {
		ps(-1);
		return;
	}
	//trav(t,ans) ps("HA",t);
	//ps("WUT",bad);
	while (sz(bad) > 1) {
		mov(bad[sz(bad)-2],bad[sz(bad)-1],0);
		mov(bad[sz(bad)-2],bad[sz(bad)-1],1);
		bad.pop_back();
		bad.pop_back();
	}
	if (tmp != sz(ans)) {
		ps("??",tmp,sz(ans),vv); 
		trav(t,ori) cout << t << " ";
		cout << "\n";
		exit(0);
	}
	// ps(v);
	ps(tmp,sz(ans));
	trav(t,ans) ps(t.f,t.s);
}
 
int main() {
    setIO();
    int T; re(T);
    F0R(i,T) solve();
}
 
/* stuff you should look for
    * int overflow, array bounds
    * special cases (n=1?), set tle
    * do smth instead of nothing and stay organized
*/

Compilation message

cat.cpp: In function 'void io::setIn(std::__cxx11::string)':
cat.cpp:110:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     void setIn(string s) { freopen(s.c_str(),"r",stdin); }
                            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
cat.cpp: In function 'void io::setOut(std::__cxx11::string)':
cat.cpp:111:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     void setOut(string s) { freopen(s.c_str(),"w",stdout); }
                             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 376 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 27 ms 504 KB Output is correct
2 Correct 27 ms 504 KB Output is correct

Subtask #3
25.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 376 KB Output is correct
2 Correct 27 ms 504 KB Output is correct
3 Correct 27 ms 504 KB Output is correct
4 Correct 30 ms 632 KB Output is correct
5 Correct 13 ms 504 KB Output is correct
6 Correct 10 ms 504 KB Output is correct

Subtask #4
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 27 ms 504 KB Output is correct
2 Correct 27 ms 504 KB Output is correct
3 Correct 548 ms 10664 KB Output is correct
4 Correct 544 ms 9540 KB Output is correct
5 Correct 582 ms 12388 KB Output is correct

Subtask #5
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 376 KB Output is correct
2 Correct 27 ms 504 KB Output is correct
3 Correct 27 ms 504 KB Output is correct
4 Correct 30 ms 632 KB Output is correct
5 Correct 13 ms 504 KB Output is correct
6 Correct 10 ms 504 KB Output is correct
7 Correct 548 ms 10664 KB Output is correct
8 Correct 544 ms 9540 KB Output is correct
9 Correct 582 ms 12388 KB Output is correct
10 Correct 538 ms 10248 KB Output is correct
11 Correct 513 ms 8160 KB Output is correct
12 Correct 549 ms 10584 KB Output is correct
13 Correct 617 ms 12660 KB Output is correct
14 Correct 542 ms 10764 KB Output is correct