Submission #936323

#	Time	Username	Problem	Language	Result	Execution time	Memory
936323		peterandvoi	Gondola (IOI14_gondola)	C++17	55 / 100	24 ms	7004 KiB

gondola

#include <bits/stdc++.h>

#include "gondola.h"

using namespace std;

#ifdef ngu
#include "debug.h"
#else
#define debug(...) 42
#endif

const int N = 250005;

int cnt[N];

int shift(int i, int j, int n) {
    i += j;
    if (i < 1) {
        i += n;
    }
    if (i > n) {
        i -= n;
    }
    return i;
}

int valid(int n, int inputSeq[]) {
    memset(cnt, 0, sizeof(cnt));
    for (int i = 0; i < n; ++i) {
        assert(inputSeq[i] < N);
        if (cnt[inputSeq[i]]) {
            return 0;
        }
        cnt[inputSeq[i]]++;
    }
    int delta = 0;
    for (int i = 0; i < n; ++i) {
        if (inputSeq[i] <= n) {
            int j = inputSeq[i];
            delta = j - i - 1;
            break;
        }
    }
    for (int i = 0; i < n; ++i) {
        if (inputSeq[i] <= n) {
            int j = shift(i + 1, delta, n);
            if (j != inputSeq[i]) {
                return 0;
            }
        }
    }
    return 1;
}

int pos[N];

int replacement(int n, int gondolaSeq[], int replacementSeq[]) {
    memset(pos, -1, sizeof(pos));
    for (int i = 0; i < n; ++i) {
        pos[gondolaSeq[i]] = i;
    }
    set<int> cur;
    for (int i = 0; i < n; ++i) {
        cur.insert(i);
    }
    for (int i = 0; i < n; ++i) {
        if (gondolaSeq[i] <= n) {
            cur.erase(i);
        }
    }
    int delta = 0;
    for (int i = 0; i < n; ++i) {
        if (gondolaSeq[i] <= n) {
            int j = gondolaSeq[i];
            delta = j - i - 1;
            break;
        }
    }
    for (int i = 0; i < n; ++i) {
        gondolaSeq[i] = shift(i + 1, delta, n);
    }
    int m = -1;
    for (int i = n + 1; i < N; ++i) {
        if (!cur.size()) {
            break;
        }
        int j = *cur.begin();
        if (pos[i] != -1) {
            j = pos[i];
            cur.erase(j);
        }
        replacementSeq[++m] = gondolaSeq[j];
        gondolaSeq[j] = i;
    }
    return m + 1;
}

const int MOD = (int) 1e9 + 9;

int countReplacement(int n, int inputSeq[]) {
    assert(0);
    if (valid(n, inputSeq) == 0) {
        return 0;
    }
    memset(pos, -1, sizeof(pos));
    for (int i = 0; i < n; ++i) {
        pos[inputSeq[i]] = i;
    }
    int cnt = n;
    for (int i = 0; i < n; ++i) {
        if (inputSeq[i] <= n) {
            cnt--;
        }
    }
    int res = 1;
    int delta = 0;
    for (int i = 0; i < n; ++i) {
        if (inputSeq[i] <= n) {
            int j = inputSeq[i];
            delta = j - i - 1;
            break;
        }
    }
    for (int i = 0; i < n; ++i) {
        inputSeq[i] = shift(i + 1, delta, n);
    }
    assert(n != 2);
    if (n == 2 && cnt < 2) {
        return 1;
    }
    for (int i = n + 1; i < N; ++i) {
        if (!cnt) {
            break;
        }
        if (pos[i] != -1) {
            cnt--;
        } else {
            res = 1LL * res * cnt % MOD;
        }
    }
    if (n == 2) {
        res = 1LL * res * 2 % MOD;
    }
    return res;
}

• 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: 0 / 5
• Subtask 8: 0 / 15
• Subtask 9: 0 / 15
• Subtask 10: 0 / 10