lists_1

#include <iostream>
#include <cstring>

struct Node {
    double data;
    Node* next;
};

Node* toCur(Node* first, Node* cur) {
    while (first->next != cur) {
        first = first->next;
    }
    return first;
}

Node* addNode(Node* first, double data) {
    if (first == NULL) {
        first = new Node;
        first->data = data;
        first->next = NULL;
    }
    else {
        Node* tmp = new Node;
        tmp->data = data;
        tmp->next = NULL;
        toCur(first, NULL)->next = tmp;
    }
    return first;
}

Node* delNode(Node* first, Node* cur) {
    if (cur == first) {
        first = cur->next;
        delete cur;
    }
    else if (cur == toCur(first, NULL)) {
        toCur(first, cur)->next = NULL;
        delete cur;
    }
    else {
        toCur(first, cur)->next = cur->next;
        delete cur;
    }
    return first;
}

Node* sortInsert(Node* first, double data) {
    if (first == NULL) {
        first = addNode(first, data);
    }
    else {
        Node* cur = first;
        while ((cur->data > data) && (cur->next != NULL)) {
            cur = cur->next;
        }
        if (cur->data > data) {
            first = addNode(first, data);
        }
        else if (cur == first) {
            Node *tmp = new Node;
            tmp->data = data;
            tmp->next = cur;
            first = tmp;
        }
        else {
            Node *tmp = new Node;
            tmp->data = data;
            tmp->next = cur;
            toCur(first, cur)->next = tmp;
        }
    }
    return first;
}

Node* listFromFile(FILE* f, Node* first) {
    char str[127];
    fgets(str, 127, f);
    puts(str);
    char* ptr = strtok(str, " ");
    while (ptr != NULL) {
        first = sortInsert(first, atof(ptr));
        ptr = strtok(NULL, " ");
    }
    return first;
}

Node* delLess(Node* first, int num) {
    Node* cur = first;
    while (cur->data < num) {
        cur = delNode(first, cur);
        first = cur;
    }
    while (cur != NULL) {
        if (cur->data < num) {
            cur = delNode(first, cur);
            first = cur;
        }
        cur = cur->next;
    }
    return first;
}

void printList(Node* first) {
    while (first != NULL) {
        printf("%lf ", first->data);
        first = first->next;
    }
}

void delList(Node*& first) {
    while (first != NULL) {
        Node* tmp = first;
        first = first->next;
        delete tmp;
    }
}

int main() {
    FILE* f;
    f = fopen(R"(C:\Clion Projects\lists\test.txt)", "r");
    Node* first = NULL;
    first = listFromFile(f, first);
    fclose(f);
    first = delLess(first, 2);
    printList(first);
    delList(first);
    return 0;
}