Submission #259430

#	Time	Username	Problem	Language	Result	Execution time	Memory
259430		Benq	Swap (BOI16_swap)	C++14	100 / 100	128 ms	23160 KiB

swap

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef double db; 
typedef string str; 
 
typedef pair<int,int> pi;
typedef pair<ll,ll> pl; 
typedef pair<db,db> pd; 
 
typedef vector<int> vi; 
typedef vector<ll> vl; 
typedef vector<db> vd; 
typedef vector<str> vs; 
typedef vector<pi> vpi;
typedef vector<pl> vpl; 
typedef vector<pd> vpd; 
 
#define mp make_pair
#define f first
#define s second
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend() 
#define rsz resize
#define ins insert 
#define ft front() 
#define bk back()
#define pf push_front 
#define pb push_back
#define eb emplace_back 
#define lb lower_bound 
#define ub upper_bound 
 
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)
 
const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5; 
const ll INF = 1e18; 
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; 
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 
 
template<class T> bool ckmin(T& a, const T& b) { 
	return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { 
	return a < b ? a = b, 1 : 0; } 
constexpr int pct(int x) { return __builtin_popcount(x); } 
constexpr int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
ll cdiv(ll a, ll b) { return a/b+((a^b)>0&&a%b); } // divide a by b rounded up
ll fdiv(ll a, ll b) { return a/b-((a^b)<0&&a%b); } // divide a by b rounded down
ll half(ll x) { return fdiv(x,2); }
 
template<class T, class U> T fstTrue(T lo, T hi, U f) { 
	// note: if (lo+hi)/2 is used instead of half(lo+hi) then this will loop infinitely when lo=hi
	hi ++; assert(lo <= hi); // assuming f is increasing
	while (lo < hi) { // find first index such that f is true 
		T mid = half(lo+hi);
		f(mid) ? hi = mid : lo = mid+1; 
	} 
	return lo;
}
template<class T, class U> T lstTrue(T lo, T hi, U f) {
	lo --; assert(lo <= hi); // assuming f is decreasing
	while (lo < hi) { // find first index such that f is true 
		T mid = half(lo+hi+1);
		f(mid) ? lo = mid : hi = mid-1;
	} 
	return lo;
}
template<class T> void remDup(vector<T>& v) { 
	sort(all(v)); v.erase(unique(all(v)),end(v)); }
 
// INPUT
template<class A> void re(complex<A>& c);
template<class A, class B> void re(pair<A,B>& p);
template<class A> void re(vector<A>& v);
template<class A, size_t SZ> void re(array<A,SZ>& a);
 
template<class T> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); }
 
template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; }
template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); }
template<class A> void re(vector<A>& x) { trav(a,x) re(a); }
template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); }
 
// TO_STRING
#define ts to_string
str ts(char c) { return str(1,c); }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
str ts(bool b) { 
	#ifdef LOCAL
		return b ? "true" : "false"; 
	#else 
		return ts((int)b);
	#endif
}
template<class A> str ts(complex<A> c) { 
	stringstream ss; ss << c; return ss.str(); }
str ts(vector<bool> v) {
	str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]);
	res += "}"; return res; }
template<size_t SZ> str ts(bitset<SZ> b) {
	str res = ""; F0R(i,SZ) res += char('0'+b[i]);
	return res; }
template<class A, class B> str ts(pair<A,B> p);
template<class T> str ts(T v) { // containers with begin(), end()
	#ifdef LOCAL
		bool fst = 1; str res = "{";
		for (const auto& x: v) {
			if (!fst) res += ", ";
			fst = 0; res += ts(x);
		}
		res += "}"; return res;
	#else
		bool fst = 1; str res = "";
		for (const auto& x: v) {
			if (!fst) res += " ";
			fst = 0; res += ts(x);
		}
		return res;
 
	#endif
}
template<class A, class B> str ts(pair<A,B> p) {
	#ifdef LOCAL
		return "("+ts(p.f)+", "+ts(p.s)+")"; 
	#else
		return ts(p.f)+" "+ts(p.s);
	#endif
}
 
// OUTPUT
template<class A> void pr(A x) { cout << ts(x); }
template<class H, class... T> void pr(const H& h, const T&... t) { 
	pr(h); pr(t...); }
void ps() { pr("\n"); } // print w/ spaces
template<class H, class... T> void ps(const H& h, const T&... t) { 
	pr(h); if (sizeof...(t)) pr(" "); ps(t...); }
 
// DEBUG
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
	cerr << ts(h); if (sizeof...(t)) cerr << ", ";
	DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL, chk -> fake assert
	#define dbg(...) cerr << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
	#define chk(...) if (!(__VA_ARGS__)) cerr << "Line(" << __LINE__ << ") -> function(" \
		 << __FUNCTION__  << ") -> CHK FAILED: (" << #__VA_ARGS__ << ")" << "\n", exit(0);
#else
	#define dbg(...) 0
	#define chk(...) 0
#endif
 
// FILE I/O
void setIn(str s) { freopen(s.c_str(),"r",stdin); }
void setOut(str s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { ios_base::sync_with_stdio(0); cin.tie(0); }
void setIO(str s = "") {
	unsyncIO();
	// cin.exceptions(cin.failbit); 
	// throws exception when do smth illegal
	// ex. try to read letter into int
	if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
}
 
int n, p[MX];
int par[MX];
vi val[MX], child[MX];
 
int qmin(int x) {
	if (!par[x]) { assert(p[x]); return p[x]; }
	assert(p[x] == 0);
	x = par[x];
	int res = MOD;
	while (x) {
		// dbg("CURRENT",x);
		assert(sz(val[x]));
		trav(t,val[x]) ckmin(res,t);
		if (sz(val[x]) == 2) {
			assert(!par[x]);
			break;
		} else {
			assert(sz(val[x]) == 1 && par[x]);
			x = par[x];
		}
	}
	assert(res != MOD);
	return res;
}
 
void delChild(int a, int b) {
	assert(a && par[b] == a);
	auto it = find(all(child[a]),b); assert(it != end(child[a]));
	child[a].erase(it); par[b] = 0;
}
 
void setChild(int a, int b) {
	assert(a); child[a].pb(b); 
	par[b] = a; // assert(p[b]); 
	p[b] = 0;
}
 
void setEq(int x) {
	if (p[x]) return;
	int v = qmin(x);
	vi trail = {x};
	while (find(all(val[trail.bk]),v) == end(val[trail.bk])) {
		assert(trail.bk);
		trail.pb(par[trail.bk]);
	}
	// dbg("SETEQ",x,trail);
	for (;sz(trail) > 1;trail.pop_back()) {
		int t = trail.bk; assert(sz(val[t]) && sz(child[t]) == 2);
		int c = trail[sz(trail)-2], C = child[t][0]+child[t][1]-c;
		val[c].pb(v); delChild(t,c); delChild(t,C);
		if (sz(val[t]) == 2) {
			val[C].pb(val[t][0]+val[t][1]-v);
		} else {
			int P = par[t];
			delChild(P,t); setChild(P,C);
		}
	}
}
 
 
int main() {
	setIO(); re(n); 
	FOR(i,1,n+1) re(p[i]);
	FOR(i,1,n+1) {
		// dbg("DOING",i);
		if (!par[i] && sz(val[i])) {
			assert(sz(val[i]) == 1 && p[i] == 0);
			p[i] = val[i][0]; val[i] = {};
		}
		// dbg("HUH",i,p[i],par[i]);
		int x = qmin(i); int mn = x;
		if (2*i <= n) ckmin(mn,p[2*i]);
		if (2*i+1 <= n) ckmin(mn,p[2*i+1]);
		if (mn == x) setEq(i); // just remove the min
		else if (mn == p[2*i]) { // don't touch p[2*i+1]
			if (!par[i]) p[2*i] = p[i];
			else {
				int P = par[i];
				delChild(P,i);
				setChild(P,2*i);
			}
		} else {
			if (!par[i]) val[i] = {p[i],p[2*i]};
			else val[i] = {p[2*i]};
			setChild(i,2*i), setChild(i,2*i+1);
		}
		pr(mn,' ');
		// FOR(z,1,n+1) dbg(z,p[z],par[z],child[z],val[z]);
	}
	// ps("OK");
	// you should actually read the stuff at the bottom
}
 
/* stuff you should look for
	* int overflow, array bounds
	* special cases (n=1?)
	* do smth instead of nothing and stay organized
	* WRITE STUFF DOWN
*/
 

Compilation message (stderr)

swap.cpp: In function 'void setIn(str)':
swap.cpp:166:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setIn(str s) { freopen(s.c_str(),"r",stdin); }
                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
swap.cpp: In function 'void setOut(str)':
swap.cpp:167:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setOut(str s) { freopen(s.c_str(),"w",stdout); }
                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 11 / 11
• Subtask 3: 27 / 27
• Subtask 4: 20 / 20
• Subtask 5: 32 / 32