Increment n Decrement(URGENT HELP)

Question

Please help me to understand the output of this code. I am really confused. I know the output but kindly explain me its working in memory?. That single operator with operand (-a), (b=-b), (+c), (d= -c) is different for me.
int a,b,c,d;
a=b=c=d=0;
a++;
-a;
b= a++;
b= -a;
c += a - b;
c = ++c;
+c;
d = -c;
cout << a << endl;
cout << b << endl;
cout << c << endl;
cout << d << endl;

Answer 1

int a,b,c,d;
a=b=c=d=0;
a++; //a still 0 but will become 1 after this statement
-a; //a=1 now, so this one is -1
b= a++; //b=1, but a will increase by 1 after this
b= -a; //a = 2 now, so b=-2
c += a - b; // this equal to c=c+a-b or c= 0+2-(-2) = 4
c = ++c; // c increase by one first (5) then assign to c
+c; // positive c 5 nothibg change
d = -c; // d=-5
cout << a << endl;
cout << b << endl;
cout << c << endl;
cout << d << endl;

Answer 2

thanks alot, it really helped me.❤️