Program shuts down immediately SDL - c++

Question

When I run this code (from the Lazy Foo SDL tutorial) the program immediately shuts down. Why is that? I'm sorry if it gets kind of messy because of the lack of comments, but I thought that it didn't really matter since there were comments on Lazy Foo's post. I get no errors when building it.
#include "SDL/SDL_image.h"
#include "SDL/SDL.h"
#include <string>
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;
const int SCREEN_BPP = 32;
SDL_Surface *image = NULL;
SDL_Surface *screen = NULL;
SDL_Event event;
SDL_Surface *load_image (std::string filename)
{
SDL_Surface* loadedImage = NULL;
SDL_Surface* optimizedImage = NULL;
loadedImage = IMG_Load( filename.c_str());
if(loadedImage != NULL)
{
optimizedImage = SDL_DisplayFormat (loadedImage);
SDL_FreeSurface(loadedImage);
}
return optimizedImage;
}
void apply_surface (int x, int y, SDL_Surface* source, SDL_Surface* destination)
{
SDL_Rect offset;
offset.x = x;
offset.y = y;
SDL_BlitSurface (source, NULL, destination, &offset);
}
bool init()
{
if (SDL_Init(SDL_INIT_EVERYTHING) == -1)
{
return false;
}
screen = SDL_SetVideoMode (SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, SDL_SWSURFACE);
if (screen == NULL)
{
return false;
}
SDL_WM_SetCaption("Event test", NULL);
return true;
}
bool load_files()
{
image = load_image ("background.png");
if (image == NULL)
{
return false;
}
return true;
}
void clean_up()
{
SDL_FreeSurface(image);
SDL_Quit();
}
int main(int argc, char* args[])
{
bool quit = false;
if (init() == false)
{
return 1;
}
if (load_files() == false)
{
return 1;
}
apply_surface(0,0, image, screen);
if(SDL_Flip(screen) == -1)
{
return 1;
}
while(quit == false)
{
while (SDL_PollEvent(&event))
{
if(event.type == SDL_QUIT)
{
quit = true;
}
}
}
clean_up();
return 0;
}

Answer 1

If you're missing background.png, or any of the required DLL's in the executable directory, you can encounter weird crashes.
Being that this is one of the simpler programs in this series, I'd bet this is the issue. I've seen strange segfaults myself when I had a brain-fart and forgot a file, or it wasn't where the exe expected it to be.