C++ :: Why Does This Code Crash Half Way Through

whats wrong with this code, I'm trying to parse a .js file and replace all the ";" with "; " i.e add a new line after each ";". So I load the file into a char[] buffer then assign a string to this contents of this buffer. Then loop char by char through using an iterator and check for a ";", if found use replace. So int i gets to about 85898 then crashes with unknown error, 'i' should reach about 175653. It does work up till it crashes. And, is this not a simpler way to load a file into a buffer, there is in C.

Code:
#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
#include <stdlib.h>
int main()

[code]....