Binary Decoder

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

int main() {
    char str[100], output[100], buffer;
    int len, len2;

    gets(str);

    len = strlen(str);

    len2 = 0;
    buffer = 0;
    for(int i = len - 1, shift = 0; i >= 0; --i) {
        if(str[i] == '.') {
            shift = 0;
            output[len2++] = buffer;
            buffer = 0;

            continue;
        }

        if(str[i] == '1')
            buffer += (1 << shift);

        shift++;
    }

    output[len2++] = buffer;
    output[len2] = '\0';

    for(int i = len2 - 1; i >= 0; --i)
        printf("%c", output[i]);

    return 0;
}