Submission #291374

#	Time	Username	Problem	Language	Result	Execution time	Memory
291374		georgerapeanu	Gondola (IOI14_gondola)	C++11	100 / 100	29 ms	2944 KiB

gondola

#include "gondola.h"
#include <cstdio>
#include <algorithm>

using namespace std;

inline int get_in_range(int st,int dr,int val){
    int tmp = (val - st) % (dr - st + 1);

    if(tmp < 0){
        tmp += (dr - st + 1);
    }

    return tmp + st;
}

int stuff[250005];

int valid(int n, int inputSeq[])
{
    int pos = -1;
    for(int i = 0;i < n;i++){
        if(inputSeq[i] <= n){
            pos = i;
        }
    }


    for(int i = 0;i < n;i++){
        if(inputSeq[i] <= n && inputSeq[i] != get_in_range(1,n,inputSeq[pos] + i - pos)){
            return 0;
        }
    }

    sort(inputSeq,inputSeq + n);

    for(int i = 1;i < n;i++){
        if(inputSeq[i] == inputSeq[i - 1]){
            return 0;
        }
    }

    return 1;
}

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

int replacement(int n, int gondolaSeq[], int replacementSeq[])
{

    for(int i = 0;i <= 2e5;i++){
        stuff[i] = -1;
    }

    int ma = 0,ma_pos;
    int pos = -1;

    for(int i = 0;i < n;i++){
        stuff[gondolaSeq[i]] = i;
        ma = max(ma,gondolaSeq[i]);
        if(ma == gondolaSeq[i]){
            ma_pos = i;
        }
        if(gondolaSeq[i] <= n){
            pos = i;
        }
    }

    if(pos == -1){
        pos = 0;
        gondolaSeq[pos] = 1;
    }

    for(int i = 0;i < n;i++){
        gondolaSeq[i] = get_in_range(1,n,gondolaSeq[pos] + i - pos);
    }

    int len = 0;

    for(int i = n + 1;i <= ma;i++){
        if(stuff[i] == -1){
            replacementSeq[len++] = gondolaSeq[ma_pos];
            gondolaSeq[ma_pos] = i;
        }
        else{
            replacementSeq[len++] = gondolaSeq[stuff[i]];
            gondolaSeq[stuff[i]] = i;
        }
    }

    return len;
}

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

const int MOD = 1e9 + 9;

int lgpow(int b,int e){
    int p = 1;

    while(e){
        if(e & 1){
            p = 1LL * p * b % MOD;
        }
        b = 1LL * b * b % MOD;
        e >>= 1;
    }

    return p;
}

int countReplacement(int n, int inputSeq[])
{
    if(valid(n,inputSeq) == 0){
        return 0;
    }

    int ans = n;

    for(int i = 0;i < n;i++){
        if(inputSeq[i] <= n){
            ans = 1;
        }
    }


    sort(inputSeq,inputSeq + n);

    for(int i = n - 1;i >= 0;i--){
        if(inputSeq[i] <= n){
            break;
        }
        int curr = inputSeq[i];
        int nxt = ((i == 0 || inputSeq[i - 1] < n) ? n:inputSeq[i - 1]);
        ans = 1LL * ans * lgpow(n - i,curr - nxt - 1) % MOD;
    }

    return ans;
}

Compilation message (stderr)

gondola.cpp: In function 'int replacement(int, int*, int*)':
gondola.cpp:82:48: warning: 'ma_pos' may be used uninitialized in this function [-Wmaybe-uninitialized]
   82 |             replacementSeq[len++] = gondolaSeq[ma_pos];
      |                                                ^~~~~~

• 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