Submission #136582

#	Time	Username	Problem	Language	Result	Execution time	Memory
136582		mosesmayer	Gondola (IOI14_gondola)	C++17	100 / 100	39 ms	3588 KiB

gondola

#include "gondola.h"
#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define ALL(x) x.begin(), x.end()
using namespace std;
typedef long long LL;
typedef vector<int> vi;
typedef pair<int,int> pii;

int valid(int n, int inputSeq[]){
	vi a(inputSeq, inputSeq + n);

	// handle whether all values are unique
	vi b(a.begin(), a.end());
	sort(ALL(b)); b.erase(unique(ALL(b)), b.end());
	if (b.size() != a.size()) return 0;

	// handle min element
	vi::iterator mnit = min_element(a.begin(), a.end());
	int mn = *mnit, pos = mnit - a.begin();
	if (mn >= n) return 1;
	
	// rotate elements so that min is at first position.
	// now index i will be original position of (mn + i - 1)%n + 1;
	rotate(a.begin(), a.begin() + pos, a.end());
	// validity check
	for (int i = 0; i < n; i++){
		if (a[i] > n) continue;
		if (a[i] != ((mn + i - 1) % n + 1)) return 0;
	}
	return 1;
}

//----------------------

int replacement(int n, int gondolaSeq[], int replacementSeq[]){
	vi a(gondolaSeq, gondolaSeq + n);
	// get length
	int len = (*max_element(a.begin(), a.end())) - n;

	vi::iterator mnit = min_element(a.begin(), a.end());
	int mn = *mnit, pos = mnit - a.begin();

	if (mn < n){
		rotate(a.begin(), a.begin() + pos, a.end());
	} else {
		pos = 0;
	}
	vector<pii> rep; // to be replaced
	for (int i = 0; i < n; i++){
		int oriNum = mn < n ? ((mn + i - 1) % n) + 1 : i+1;
		if (a[i] > n || a[i] != oriNum){
			rep.eb(a[i], oriNum);
		}
	}
	sort(rep.begin(), rep.end());
	int cur = n+1, idx = 0;
	for (int i = 0; i < rep.size(); i++){
		int prv = rep[i].se;
		while (cur <= rep[i].fi){
			replacementSeq[idx++] = prv;
			prv = cur;
			cur++;
		}
	}
	return len;
}

//----------------------

const LL mod = 1e9 + 9;
LL fpow(LL b, LL e, LL m = mod){
	LL r = 1;
	for (; e > 0; e >>= 1){
		if (e&1) (r *= b) %= m;
		(b *= b) %= m;
	}
	return r;
}
int countReplacement(int n, int inputSeq[]){
	if (!valid(n, inputSeq)) return 0;
	vi a(inputSeq, inputSeq + n);

	vi::iterator mnit = min_element(a.begin(), a.end());
	int mn = *mnit, pos = mnit - a.begin();

	rotate(a.begin(), a.begin() + pos, a.end());

	vector<pii> rep;
	LL tot = 1;

	int cur = n;
	for (int i = 0; i < n; i++){
		int oriNum = (mn + i - 1) % n + 1;
		if (a[i] != oriNum)
			rep.eb(a[i], oriNum);
		else cur--;
	}
	sort(rep.begin(), rep.end());
	int prv = n;
	for (pii p : rep){
		(tot *= fpow(cur, p.fi - prv - 1)) %= mod;
		cur--;
		prv = p.fi;
	}
	if (mn > n){
		(tot *= n) %= mod;
	}
	return tot;
}

Compilation message (stderr)

gondola.cpp: In function 'int replacement(int, int*, int*)':
gondola.cpp:61:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < rep.size(); i++){
                  ~~^~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 10 / 10
• Subtask 4: 5 / 5
• Subtask 5: 10 / 10
• Subtask 6: 20 / 20
• Subtask 7: 5 / 5
• Subtask 8: 15 / 15
• Subtask 9: 15 / 15
• Subtask 10: 10 / 10