C: function: Function: Implements the reverse storage and output of all letters in the character array

The first two days of small test encountered a problem, the establishment of a function, function: To achieve the character array of all the letters in reverse storage and output, initially feel simple with a number array, run a lot of errors found in the format, these are unnecessary errors, now, let's say the code idea: Define a character array if there are n characters, let a pointer variable *p point to the first address, * (p+n-1) is the end address, and then achieve *p and * (p+n-1) value interchange, this way let *q=* (p+n-1) every change, p++, q--, when P>q exits the loop, let's look at the code:

1#include"stdio.h"2 CharChangeChar*p,inty);3 voidMain ()4 {5     Chara[6]="abcdef";6Change (A,6); 7printf"%s", a);8 }9 CharChangeChar*p,inty)Ten { One     Char*Q; A     inttemp;//This side is more prone to wrong, some qualitative thinking, will be defined as char type; -q=p+y-1; -      while(p<q) the     { -temp=*p; -*p=*Q; -*q=temp; +p++; -q--; +         } A}

Here just make n=6, see more clearly, to complicate a bit, we can also enter the letter, want a few on a few, this time I use get () to input, if input n, then how do we know this value of N, we can first define *P1 let P=a, both point to the first address, If you exceed the last address, which is * (P+n) ==0, this gives us a condition to end the loop:

#include"stdio.h"voidMain () {Chara[ +];    Gets (a); Char*p; intI,n; I=0; P=A;  while(* (p+i)! =0) {i++; } N=i; printf ("%d", n);}

The code above can be used to find out the number of letters we enter manually, plus the change () function:

#include"stdio.h"CharChangeChar*p,inty);voidMain () {Chara[ +]; printf ("input letter:\n");    Gets (a); Char*P1; intI,n; I=0; P1=A;  while(* (p1+i)! =0)//exceeds the address result of 0 {i++; } N=i;    Change (a,n); printf ("output:\n%s", a);}CharChangeChar*p,inty) {    Char*Q; inttemp; Q=p+y-1;  while(p<q) {temp=*p; *p=*Q; *q=temp; P++; Q--; }}

Run Result: If the number array is similar.

C: function: Function: Implements the reverse storage and output of all letters in the character array