将数组保存到文件将无法正常工作，程序崩溃

I posted a few days ago already about a problem with my array-program. Well, it is basically a program which lets the user generate an array, safe a specific number in a specific slot, read the array or read a specific slots value. Now I am figuring out, how to let the user save the current array as a file. I posted a few days ago already about a problem