CODEWITHSUNDEEP
c++
Daniel Pawłowski
Daniel Pawłowski

Reputation: 43

std::bad_array_new_length for large numbers

I try to run following code:

#include <stdio.h>
#include <stdlib.h>

int find_next(int act, unsigned long long survivors[], int n)
{
    int i = act;
    while (survivors[i] == 0)
    {
        i++;
        i = i % n;
    }
    i = (i + 1) % n; // found first one, but need to skip 
    while (survivors[i] == 0)
    {
        i++;
        i = i % n;

    }// thats the guy 
    return i;
}
int main()
{
    long long int lines;
    long long int* results;

    scanf_s("%llu", &lines);
    results = new long long int[lines];

    for (long long int i = 0; i < lines; i++) {
        unsigned long long n, k;

        scanf_s("%llu", &n);
        scanf_s("%llu", &k);
        unsigned long long* survivors;
        survivors = new unsigned long long[n];
        for (int m = 0; m < n; m++) {
            survivors[m] = 1;
        }
        int* order;
        order = new int[n];
        int p = 0;
        int act = 0;
        while (p < n - 1)
        {
            act = find_next(act, survivors, n);
            order[p] = act;
            survivors[act] = 0; // dies; 
            p++;
        }
        order[p] = find_next(act, survivors, n);

        if (k > 0)
        {
            results[i] = order[k - 1] + 1;
        }
        else
        {
            results[i] = order[n + k] + 1;
        }
        delete[] survivors;
        delete[] order;
    }
    for (long long int i = 0; i < lines; i++) {
        printf("%llu\n", results[i]);
    }
    delete[] results;
    return 0;
}

My inputs are:
1
1111111111
-1

I am getting an exeption:

std::bad_array_new_length for large numbers

At line:

survivors = new unsigned long long[n];

How should I fix it that it wont show for such large numbers?

So far I tried all numeric types of n -> long long int, unsigned long and so on but everytime I was failing. Or maybe there is no way around that?

Upvotes: 0

Views: 445

Answers (1)

eerorika
eerorika

Reputation: 238461

How should I fix it that it wont show for such large numbers?

  • Run the program on a 64 bit CPU.
  • Use a 64 bit operating system.
  • Compile the program in 64 bit mode.
  • Install sufficient amount of memory. That array alone uses over 8 gigabytes.
  • Configure operating system to allow that much memory be allocated for the process.

P.S. Avoid owning bare pointers. In this case, I recommend using a RAII container such as std::vector.

Upvotes: 1

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