#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <locale.h>
#include <string.h>
#include <stdlib.h>
#include <float.h>
#define NAME "array.bin"

void CreateFile(const char* file) {
    FILE* f = fopen(file, "wb");
    if (!f) {
        printf("Не получилось открыть файл\n");
        return;
    }
    rewind(f);
    int n;
    printf("Введите количество элементов(компонент)\n");
    scanf("%d", &n);
    printf("Введите %d элементов:\n", n);
    for (int i = 0; i < n; i++) {
        double cur_num;
        scanf("%lf", &cur_num);
        fwrite(&cur_num, sizeof(double), 1, f);
    }
    fclose(f);
}


void PrintFile(const char* file) {
    FILE* f = fopen(file, "rb");
    if (!f) {
        printf("Не получилось открыть файл\n");
        return;
    }
    printf("Содержимое файла:\n");
    rewind(f);
    while (!feof(f)) {
        double el;
        fread(&el, sizeof(double), 1, f);
        if (!feof(f)) {
            printf("%lf\t", el);
        }
    }
    printf("\n");
    fclose(f);
}


void Change(const char* file) {
    FILE* f = fopen(file, "r+b");
    if (!f) {
        printf("Не удалось открыть файл\n");
        return;
    }
    rewind(f);
    double minimal = 10000000.0;
    int cur_id = 0;
    int id_of_min = 0;
    int id_of_negative = 0;
    while (!feof(f)) {
        cur_id++;
        double cur;
        fread(&cur, sizeof(double), 1, f);
        if (!feof(f) && cur_id % 2 == 0 && cur < minimal) {
            id_of_min = cur_id;
            minimal = cur;
        }
        if (!feof(f) && cur < 0) {
            id_of_negative = cur_id;
        }
    }
    if (id_of_negative == 0) {
        fseek(f, 0, SEEK_END);
        fwrite(&minimal, sizeof(double), 1, f);
    }
    else {
        cur_id--;
        id_of_min--;
        id_of_negative--;
        int j = id_of_negative + 1;
        while (cur_id>=j) {
            fseek(f, cur_id * sizeof(double), SEEK_SET);
            double cur;
            fread(&cur, sizeof(double), 1, f);
            fwrite(&cur, sizeof(double), 1, f);
            cur_id--;
        }
        fseek(f, sizeof(double) * (id_of_negative + 1), SEEK_SET);
        fwrite(&minimal, sizeof(double), 1, f);
    }
    fclose(f);
}

int main()
{
    setlocale(LC_ALL, "RUS");
    CreateFile(NAME);
    Change(NAME);
    PrintFile(NAME);
    return 0;
}