Submission #229210

#	Time	Username	Problem	Language	Result	Execution time	Memory
229210		rqi	Sorting (IOI15_sorting)	C++14	100 / 100	226 ms	22632 KiB

sorting

#include "sorting.h"
#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}; 

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; } 
int pct(int x) { return __builtin_popcount(x); } 
int bit(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
int cdiv(int a, int b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0 

// 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
template<class A, class B> str ts(pair<A,B> p);
template<class A> str ts(complex<A> c) { return ts(mp(c.real(),c.imag())); }
str ts(bool b) { return b ? "true" : "false"; }
str ts(char c) { str s = ""; s += c; return s; }
str ts(str s) { return s; }
str ts(const char* s) { return (str)s; }
str ts(vector<bool> v) { 
	bool fst = 1; str res = "{";
	F0R(i,sz(v)) {
		if (!fst) res += ", ";
		fst = 0; res += ts(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 T> str ts(T v) {
	bool fst = 1; str res = "{";
	for (const auto& x: v) {
		if (!fst) res += ", ";
		fst = 0; res += ts(x);
	}
	res += "}"; return res;
}
template<class A, class B> str ts(pair<A,B> p) {
	return "("+ts(p.f)+", "+ts(p.s)+")"; }

// 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 << to_string(h); if (sizeof...(t)) cerr << ", ";
	DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 42
#endif

// FILE I/O
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { ios_base::sync_with_stdio(0); cin.tie(0); }
void setIO(string 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
}

mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 

const int mx = 1000005;
int N;

vi p;
bool visited[mx];

void search(int node){
	if(visited[node]) return;
	visited[node] = 1;
	search(p[node]);
}

int getSwapNum(vi perm){
	p = perm;
	for(int i = 0; i < N; i++){
		visited[i] = 0;
	}
	int num = 0;
	for(int i = 0; i < N; i++){
		if(!visited[i]){
			search(i);
			num++;
		}
	}
	return N-num;
}

vpi getSwaps(vi perm){
	vi iperm(N, 0);
	for(int i = 0; i < N; i++){
		iperm[perm[i]] = i;
	}
	vpi ans;
	for(int i = 0; i < N; i++){
		if(iperm[i] != i){
			int a = perm[i];
			int pos = iperm[i];
			ans.pb(mp(i, a));
			swap(perm[iperm[i]], perm[i]);
			iperm[i] = i;
			iperm[a] = pos;
		}
	}
	return ans;
}

int findSwapPairs(int _N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
	N = _N;

   	vi perm(N, 0);
   	bool works = 1;
   	for(int i = 0; i < N; i++){
   		perm[i] = S[i];
   		if(perm[i] != i) works = 0;
   	}
   	if(works == 1) return 0;
   	int R = 0;

   	int lo = 1;
   	int hi = M; 

   	while(lo < hi){
   		int mid = (lo+hi)/2; // last swap index
   		vi b = perm;
   		for(int i = 0; i < mid; i++){
   			swap(b[X[i]], b[Y[i]]);
   		}

   		if(getSwapNum(b) <= mid){
   			hi = mid;
   		}
   		else{
   			lo = mid+1;
   		}
   	}

   	R = lo;

   	for(int i = 0; i < R; i++){
   		swap(perm[X[i]], perm[Y[i]]);
   	}
   	for(int i = 0; i < R; i++){
 		P[i] = Q[i] = 0;
 	}
 	vpi sw = getSwaps(perm);
 	//ps(perm);
 	//ps(sw);
 	int swind = 0;
 	perm = vector<int>(N, 0);
 	vi iperm(N, 0);
 	for(int i = 0; i < N; i++){
 		iperm[i] = perm[i] = i;	
 	}

 	for(int i = R-1; i >= 0; i--){
 		if(swind == sz(sw)) break;
 		P[i] = iperm[sw[swind].f];
 		Q[i] = iperm[sw[swind].s];
 		swap(iperm[perm[X[i]]], iperm[perm[Y[i]]]);
 		swap(perm[X[i]], perm[Y[i]]);
 		swind++;
 	}

	return R;
}

Compilation message (stderr)

sorting.cpp: In function 'void setIn(std::__cxx11::string)':
sorting.cpp:124:31: 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); }
                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
sorting.cpp: In function 'void setOut(std::__cxx11::string)':
sorting.cpp:125:32: 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: 8 / 8
• Subtask 2: 12 / 12
• Subtask 3: 16 / 16
• Subtask 4: 18 / 18
• Subtask 5: 20 / 20
• Subtask 6: 26 / 26