제출 #652274

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
652274		alvinpiter	곤돌라 (IOI14_gondola)	C++17	100 / 100	49 ms	5008 KiB

gondola

#include "gondola.h"
#include<bits/stdc++.h>
using namespace std;
#define LL long long int
#define MOD 1000000009

LL fastExponentiation(LL base, LL p) {
  if (p == 0)
    return 1;

  LL half = fastExponentiation(base, p/2);
  LL halfhalf = (half * half)%MOD;

  if (p % 2 == 0)
    return halfhalf;
  else
    return (halfhalf * base)%MOD;
}

/*
* If there is a duplicated gondola, return 0.
* If all gondolas are > n, return 1.
* Otherwise, find the position of one of the original gondola, let this be idxOfOriginalGondola.
  Start from idxOfOriginalGondola, go around the circle and make sure all other original gondolas
  are in place.
*/
int valid(int n, int gondolas[]) {
  set<int> uniqGondolas;
  int idxOfOriginalGondola = -1;

  for (int i = 0; i < n; i++) {
    uniqGondolas.insert(gondolas[i]);
    if (gondolas[i] <= n) {
      idxOfOriginalGondola = i;
    }
  }

  if (uniqGondolas.size() < n) {
    return 0;
  }

  if (idxOfOriginalGondola == -1) {
    return 1;
  }

  for (int i = idxOfOriginalGondola, step = 0; step < n; i = (i + 1)%n, step++) {
    if (gondolas[i] <= n && gondolas[i] != (gondolas[idxOfOriginalGondola] - 1 + step)%n + 1) {
      return 0;
    }
  }

  return 1;
}

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

int replacement(int n, int gondolaSeq[], int replacementSeq[])
{
  int id[n + 3];
  int oriIdx = -1;
  for (int i = 0; i < n; i++) {
    if (gondolaSeq[i] <= n) {
      oriIdx = i;
      break;
    }
  }

  if (oriIdx == -1) {
    for (int i = 0; i < n; i++) {
      id[i] = i + 1;
    }
  } else {
    for (int i = oriIdx, currentId = gondolaSeq[oriIdx], rep = 1; rep <= n; i = (i + 1)%n, rep++) {
      id[i] = currentId;
      currentId = (currentId == n ? 1 : currentId + 1);
    }
  }

  vector<pair<int, int> > newGondolasWithOriId;
  for (int i = 0; i < n; i++) {
    if (gondolaSeq[i] > n) {
      newGondolasWithOriId.push_back({gondolaSeq[i], id[i]});
    }
  }

  // Process from the smallest
  sort(newGondolasWithOriId.begin(), newGondolasWithOriId.end());

  int cntReplacement = 0;
  int lastGondola = n;
  for (auto [newGondola, oriId]: newGondolasWithOriId) {
    replacementSeq[cntReplacement++] = oriId;
    for (int g = lastGondola + 1; g < newGondola; g++) {
      replacementSeq[cntReplacement++] = g;
    }

    lastGondola = newGondola;
  }

  return cntReplacement;
}

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

int countReplacement(int n, int gondolas[]) {
  if (!valid(n, gondolas)) {
    return 0;
  }

  vector<int> largerThanN;
  for (int i = 0; i < n; i++) {
    if (gondolas[i] > n) {
      largerThanN.push_back(gondolas[i]);
    }
  }

  int cntReplaced = largerThanN.size();

  sort(largerThanN.begin(), largerThanN.end());

  vector<int> gapSizes;
  for (int i = 0; i < largerThanN.size(); i++) {
    int prev = (i == 0 ? n : largerThanN[i - 1]);
    int gapSize = largerThanN[i] - prev - 1;
    gapSizes.push_back(gapSize);
  }

  // cout << "cntReplaced: " << cntReplaced << endl;
  // cout << "gapSizes:"; for (auto gapSize: gapSizes) cout << " " << gapSize;
  // cout << endl;

  LL result = 1;
  for (int i = 0; i < gapSizes.size(); i++) {
    // cout << "hihi " << cntReplaced - i << " " << gapSizes[i] << endl;
    LL numWays = fastExponentiation(cntReplaced - i, gapSizes[i]);
    // cout << "numWays: " << numWays << endl;
    result = (result * numWays)%MOD;
  }

  if (cntReplaced == n) {
    result = (result * n)%MOD;
  }

  return result;
}

컴파일 시 표준 에러 (stderr) 메시지

gondola.cpp: In function 'int valid(int, int*)':
gondola.cpp:38:27: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   38 |   if (uniqGondolas.size() < n) {
      |       ~~~~~~~~~~~~~~~~~~~~^~~
gondola.cpp: In function 'int countReplacement(int, int*)':
gondola.cpp:122:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  122 |   for (int i = 0; i < largerThanN.size(); i++) {
      |                   ~~^~~~~~~~~~~~~~~~~~~~
gondola.cpp:133:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  133 |   for (int i = 0; i < gapSizes.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