c++ malloc segmentation fault -

i have problem malloc(). weird. code in following. use random generator generate elements array. array opened malloc(). if array size smaller 8192, ok. if size larger 8192, shows segment fault.

void random_generator(int num, int * array) {    srand((unsigned)time(0));    int random_integer;    for(int index=0; index< num; index++){      random_integer = (rand()%10000)+1;      *(array+index) = random_integer;      cout << index << endl;   }  }  int main() {   int array_size = 10000;   int *input_array;   input_array = (int*) malloc((array_size));   random_generator(8192, input_array);    // if number larger 8192, segment fault   free(input_array); } 

malloc() takes size in bytes, not number of elements. size of int typcially 4 bytes, allocating enough memory 2500 integers. allocating array_size bytes, while should allocating array_size * sizeof(int) bytes.

so, error fixed

input_array = (int*) malloc(array_size * sizeof(int));

p.s. never assume know size of int or other data type, platform dependent. use sizeof().

p.p.s. c question, rather c++ question. if using c++, should consider using new , delete [] instead of malloc() , free(), or better yet use std::vector instead of array, neil pointed out.