reverseString

/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/*
 * File:   main.c
 * Author: NgT
 *
 * Created on July 12, 2016, 11:12 PM
 */

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

/*
 *
 */
void changeString(char *s);
void deleteChar(char *s);
char* ltrim(char s[])  ;
char* rtrim(char s[] );
char* trim(char s[]);
int main(int argc, char** argv) {
    char input[100] = "";
    printf("Enter a string: ");
    gets(input);
    printf("The old string: ");
    puts(input);
    trim(input);
    changeString(input);
    return (EXIT_SUCCESS);
}

void changeString(char *s) {
    char c[300];
    c[0] = '\0';
    int i;
    for (i = strlen(s) - 1; i >= 0; i--) {
        if (s[i] == ' ') {
            strcat(strcat(c, s + i + 1), " ");
            s[i] = '\0';
        }
        if (s[i] == '_') {
            strcat(strcat(c, s + i + 1), "_");
            s[i] = '\0'; //delete space end of string
        }
    }
    strcat(c, s);
    puts(c);
}
char* ltrim(char s[])
{
    int i=0;
    while (s[i]=='_')i++;
    if (i > 0)
    strcpy(&s[0],&s[i]);
    return s;
}
char* rtrim(char s[])
{
    int i=strlen(s)-1;
    while(s[i]=='_')i--;
    s[i+1]='\0';
    return s;
}
char* trim(char s[])
{
    ltrim(s);
    rtrim(s);
    char *ptr = strstr(s,"_");
    while(ptr!=NULL)
    {
        strcpy(ptr,ptr+1);
        ptr = strstr(s,"__");
    }
    return s;
}