Submission #296473

#	Time	Username	Problem	Language	Result	Execution time	Memory
296473		emil_physmath	Gondola (IOI14_gondola)	C++17	65 / 100	45 ms	4992 KiB

gondola

#include "gondola.h"
#include <numeric>
#include <algorithm>
#include <set>
#include <vector>
#include <iostream>
using namespace std;
using llong = long long;
#define BUGO(x) cerr << #x << " = " << x << '\n';

int valid(int n, int a[])
{
    if (set<int>(a, a + n).size() != n) return false;
    int anslen = 0;
    vector<int> must(n, -1);
    for (int i = 0; i < n; ++i)
        if (a[i] <= n) {
            for (int j = i; j < i + n; ++j) {
                must[j % n] = (a[i] + j - i) % n;
                if (!must[j % n]) must[j % n] = n;
            }
            break;
        }
    if (must[0] == -1)
        iota(must.begin(), must.end(), 1);
    for (int i = 0; i < n; ++i)
        if (must[i] > a[i]) return false;
    return true;
}

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

int replacement(int n, int a[], int ans[])
{
    int anslen = 0;
    vector<int> must(n, -1);
    for (int i = 0; i < n; ++i)
        if (a[i] <= n) {
            for (int j = i; j < i + n; ++j) {
                must[j % n] = (a[i] + j - i) % n;
                if (!must[j % n]) must[j % n] = n;
            }
            break;
        }
    if (must[0] == -1)
        iota(must.begin(), must.end(), 1);
    vector<int> inds; inds.reserve(n);
    for (int i = 0; i < n; ++i)
        if (a[i] > n)
            inds.push_back(i);
    auto comp = [&a](int l, int r) {
        return a[l] < a[r];
    };
    sort(inds.begin(), inds.end(), comp);
    int gondol = n + 1;
    for (int i: inds)
        while (must[i] < a[i]) {
            ans[anslen++] = must[i];
            must[i] = gondol++;
        }
    return anslen;
}

//----------------------
const llong mod = 1000'000'009;
llong binpow(llong a, int p) {
    if (p == 0) return 1;
    if (p % 2) return (a * binpow(a, p - 1)) % mod;
    return binpow((a * a) % mod, p / 2);
}
int countReplacement(int n, int a[])
{
    if (!valid(n, a)) return 0;
    if (*max_element(a, a + n) == n) return 1;
    vector<int> b; b.reserve(n);
    for (int i = 0; i < n; ++i)
        if (a[i] > n)
            b.push_back(a[i]);
    llong ans = 1;
    b.push_back(n);
    sort(b.begin(), b.end());
    for (int i = 0; i + 1 < b.size(); ++i)
    {
        ans *= binpow((int)b.size() - 1 - i, b[i + 1] - b[i] - 1);
        ans %= mod;
    }
    return ans;
}

Compilation message (stderr)

gondola.cpp: In function 'int valid(int, int*)':
gondola.cpp:13:35: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   13 |     if (set<int>(a, a + n).size() != n) return false;
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
gondola.cpp:14:9: warning: unused variable 'anslen' [-Wunused-variable]
   14 |     int anslen = 0;
      |         ^~~~~~
gondola.cpp: In function 'int countReplacement(int, int*)':
gondola.cpp:82:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |     for (int i = 0; i + 1 < b.size(); ++i)
      |                     ~~~~~~^~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 10
• Subtask 4: 5 / 5
• Subtask 5: 10 / 10
• Subtask 6: 20 / 20
• Subtask 7: 5 / 5
• Subtask 8: 15 / 15
• Subtask 9: 0 / 15
• Subtask 10: 0 / 10