225690437

#include <iostream>

void reverseStringByWords(char* str, char delim);

int main() {
    char str[] = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor";
    std::cout << str << std::endl;
    reverseStringByWords(str, ' ');
    std::cout << str << std::endl;
}

void swap(char* a, char* b);
void reverseString(char* begin, char* end);

void reverseStringByWords(char* str, char delim) {
    const size_t size = strlen(str);
    if (size == 0) return;

    char* strEnd = str + size;
    reverseString(str, strEnd - 1);

    char* iterator = str, *wordBegin = str;
    while (iterator != strEnd) {
        if (*iterator == delim) {
            reverseString(wordBegin, iterator - 1);
            wordBegin = iterator + 1;
        }
        iterator++;
    }
    reverseString(wordBegin, iterator - 1);
}

void reverseString(char* begin, char* end) {
    while (begin < end) {
        swap(begin++, end--);
    }
}

void swap(char* a, char* b) {
    char c = *a;
    *a = *b;
    *b = c;
}