Problem (1) every time the input the correct elements such as a, after the if statement into will print the else statement in it, and I don't know what went wrong?
Look at the if condition I think logically ok?? Seeking guidance!!
(2) input illegal elements, such as ", "the cycle then becomes three times, then enter" ", circulation becomes twice,
I don't know why, the problem of other program is always met, what reason is this excuse me??

 # include & lt; stdio.h> 
Void inversion (); 
Int main () 
{
Char a [100]={' 0 '}; 
char c; 
Int I=0, length=0; 
Do 
{
Printf (" \ nplease enter a letter (if want to exit, enter '/') : "); 
The scanf (" % c ", & amp; C); 
If (c>='a' & amp; & C<='z' | | c>='A' & amp; & C{
A [I]=c; 
i++; 
} 
The else 
{
Printf (" \ nError! Both please enter a 'letter'!" ); 
} 

} while (c!='/' & amp; & i<100); 

If (a [0]=='/') 
Printf (" \ n input element, unable to reverse "); 
Else if (a [1]=='/') 
Printf (" \ n % c there is only one element, not reverse place ", a [0]). 
The else 
{
Length=I; 
Inversion (a, length); 
Printf (" element inverse to: \ n "); 
for(i=0; iPrintf (" % c ", a [I]); 
} 

} 
Void inversion (char [], int length) 
{
Int p, q; 
Char t; 
P=0; Q=length - 1; 
While (p{
T=a, [p]. 
A [p]=a, [q]. 
A [q]=t; 
p++; 
Q -; 
} 
} 

The problem is (1) the screenshot


The problem is (2) the screenshot

Now this thank you!!!!!