revstring.c

#include <stdio.h>
#include "cs50.h"
#define S_BUFFER 20
#define L_BUFFER 900
#define empty '\0'

#define print_number(x) printf("%d", x)
#define print_string(x) printf("%s", x)

void reverse(char str[], int begin, int end);

//int words(const char sentence[ ])
//{
//    int counted = 0; // result

//    // state:
//    const char* it = sentence;
//    int inword = 0;

//    do switch(*it) {
//        case '\0':
//        case ' ': case '\t': case '\n': case '\r': // TODO others?
//            if (inword) { inword = 0; counted++; }
//            break;
//        default: inword = 1;
//    } while(*it++);

//    return counted;
//}

int words(char sentence[]){
    int i;
    int wordcount = 0;
    for (i = 0; i < strlen(sentence), i+1 < strlen(sentence); i++){
        if (sentence[i] == ' ' && sentence[i-1] != ' '){
            wordcount++;
        } else if (ispunct(sentence[i]) && sentence[i-1] != ' '){
            wordcount++;
        } else if (ispunct(sentence[i]) && sentence[i+1] != ' '){
            wordcount++;
        }
    }
    if (strlen(sentence) != 0) wordcount++;
    return wordcount;
}


//Array for holding the indices for beginning and ending of a word
int *word_begin;
int *word_end;

void stamp_words(char input[])
{
    int i;

    int begin_index = 0;
    int end_index = 0;

    //Stores the first index
    if (input[0] != empty){
        word_begin[begin_index] = 0;
        begin_index++;
    }

    for (i = 0; i < strlen(input); i++){
        if ((input[i] == ' ' && input[i-1] != ' ') || (ispunct(input[i]) && input[i-1] != ' ')) {
            word_end[end_index] = i-1;
            end_index++;
        } if ((input[i] == ' ' && input[i+1] != ' ') || (ispunct(input[i]) && input[i-1] != ' ')){
            word_begin[begin_index] = i+1;
            begin_index++;
        }
    }

    char another[L_BUFFER];
    strcpy(another, input);

    for (i = 0; i < words(input); i++){
//        printf("begin [%d] = %d\n", i, word_begin[i]);
//        printf("end [%d] = %d\n", i, word_end[i]);
//        printf("------------------------\n");
        reverse(another, word_begin[i], word_end[i]);
    }

//    reverse(another, word_begin[0], word_end[0]);
    puts(another);

}

void reverse(char str[], int begin, int end)
{
    int i = begin;
    int j = end;

    for (i = begin, j = end; i <= j; i++, j--){
        char t = str[i];
        str[i] = str[j];
        str[j] = t;
    }

}

int main(void)
{
   string in = GetString();
   char content[L_BUFFER];
   strcpy(content, in);
   int word_count = words(content);

   //Allocate memory for holding the indices
   word_begin = (int*) malloc(sizeof(int) * word_count);
   word_end = (int*) malloc(sizeof(int) * word_count);

   char delimiter[] = {' ', '\0'};
   strcat(content, delimiter);
   stamp_words(content);
}