C_Learning/reverse.c at master · TsengWen/C_Learning · GitHub

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#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define abx(x) ((x) < 0 ? -(x) : (x));

void itoa(int n, char s[]);
void reverse(char s[]);

void main(){

	int n;
	char s[100];

	n = -32456;

	printf("orgin n : %d\n",n );
	itoa( n, s);
	printf("after s : %s\n",s );


}

void itoa(int n, char s[]){

	int i , sign;
	void reverse(char s[]);

	sign = n;
	i = 0;
	do{
		s[i++] = abs(n % 10) + '0';
	}while((n /= 10) != 0);


	if (sign < 0)
	{
		s[i++] = '-';
	}
	s[i] = '\0';

}

void reverse(char s[]){

	int c , i, j;

	for (i = 0 , j = strlen(s) - 1; i < j; i++ , j--)
	{
		c = s[i];
		s[i] = s[j];
		s[j] = c;


	}


}