I am to make a linked list in C with an ordered insert function. The array lists is an array of individual linked lists and I have to generate 10000 random numbers and sometimes I can generate 300 or 400 numbers and sometimes it fails and gives me a buffer overrun exception. What is the reason for me getting this?
I thought it might be because I need to free some memory but it seems to me that I need all the memory I am allocating, nothing is left over.
When the error occurs the call stack shows this line:
struct Node *newNode = (struct Node *)malloc(sizeof(*newNode));
is what is causing the exception.
It works properly with less numbers being generated, like if I do 100 numbers the output looks like this: http://gyazo.com/18a9ba87611f5676d6fa7b6229fc41e0 That's not the full output of course but that's the idea.
// Program 6.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <time.h>
#include <stdlib.h>
#define MAX 200
void orderedInsert(struct Node **, int);
void printList(struct Node **, int);
struct List{
int size;
struct Node *front;
};
struct Node{
int value;
struct Node *next;
};
void main(){
struct List lists[MAX];
int i, random;
for(i = 0; i < MAX; i++){
lists[i].front = 0;
lists[i].size = 0;
}
srand(time(NULL));
for(i = 0; i < 100; i++){
random = rand() % 10000000;
orderedInsert( &(lists[random%MAX].front), random);
(lists[i].size)++;
}
for(i = 0; i < MAX; i++){
printf("%d ", i);
printList( &(lists[i].front), lists[i].size);
}
scanf_s("%d", NULL);
}
void orderedInsert(struct Node **front, int value){
struct Node *newNode = (struct Node *)malloc(sizeof(*newNode));
struct Node *temp,
*prev;
newNode->value = value;
if(*front == NULL){
*front = newNode;
newNode->next = 0;
return;
}
if((*front)->value > newNode->value){
newNode->next = *front;
*front = newNode;
return;
}
temp = (*front)->next;
prev = *front;
while(temp != NULL && temp->value < newNode->value){
prev = temp;
temp = temp->next;
}
newNode->next = temp;
prev->next = newNode;
}
void printList(struct Node **front, int value){
struct Node *temp;
temp = *front;
if(temp){
printf("The list contains elements: %d", temp->value);
temp = temp->next;
while(temp != NULL){
printf(", %d", temp->value);
temp = temp->next;
}
}
printf("\n");
}
Here is the full call stack if you need it-
msvcr110d.dll!_crt_debugger_hook(int _Reserved) Line 57 C
Program 6.exe!__raise_securityfailure(_EXCEPTION_POINTERS * ExceptionPointers) Line 67 C
Program 6.exe!__report_gsfailure() Line 235 C
msvcr110d.dll!ValidateLocalCookies(void (unsigned int) * CookieCheckFunction, _EH4_SCOPETABLE * ScopeTable, char * FramePointer) Line 198 C
msvcr110d.dll!_except_handler4_common(unsigned int * CookiePointer, void (unsigned int) * CookieCheckFunction, _EXCEPTION_RECORD * ExceptionRecord, _EXCEPTION_REGISTRATION_RECORD * EstablisherFrame, _CONTEXT * ContextRecord, void * DispatcherContext) Line 329 C
Program 6.exe!_except_handler4(_EXCEPTION_RECORD * ExceptionRecord, _EXCEPTION_REGISTRATION_RECORD * EstablisherFrame, _CONTEXT * ContextRecord, void * DispatcherContext) Line 94 C
ntdll.dll!77e2b499() Unknown
[Frames below may be incorrect and/or missing, no symbols loaded for ntdll.dll]
ntdll.dll!77e2b46b() Unknown
ntdll.dll!77e2b40e() Unknown
ntdll.dll!77de0133() Unknown
msvcr110d.dll!malloc(unsigned int nSize) Line 56 C++
> Program 6.exe!orderedInsert(Node * * front, int value) Line 59 C
Program 6.exe!main(...) Line 42 C
Program 6.exe!__tmainCRTStartup() Line 536 C
cd001c1d() Unknown
I got another error: Unhandled exception at 0x100B26B6 (msvcr110d.dll) in Program 6.exe: 0xC0000005: Access violation reading location 0x0146F78F.
Call stack for this one:
> msvcr110d.dll!_nh_malloc_dbg_impl(unsigned int nSize, int nhFlag, int nBlockUse, const char * szFileName, int nLine, int * errno_tmp) Line 239 C++
Program 6.exe!orderedInsert(Node * * front, int value) Line 59 C
Program 6.exe!main(...) Line 42 C
Program 6.exe!__tmainCRTStartup() Line 536 C
a500201d() Unknown
This isn't the full call stack. The full call stack is miles long.
