#include<stdio.h>
#include<stdlib.h>
#include<time.h>

void fillArrayRange(int arr[], int size, int from, int to);
void printArr(int ar[], int size);
void sortDescending(int ar[], int size);
void swap(int arr[], int size, int i, int j);
void printArr(int ar[], int size);
void sortInRange(int ar[], int size, int start, int end);
void evenFirst(int ar[], int size);
void evenFirst2(int ar[], int size);
int flag(int arr[], int size);
int search(int arr[], int size, int number);

int main() {
	int size = 10, from = -10, to = 10, start = -15, end = 10, number = -2;
	int array[size];
	//=============Check values==================
	if (size > 1 || from > to)
		fillArrayRange(array, size, from, to);
	else {
		printf("Invalid value");
		return 0;
	}
	//=============END Check values==============
	printArr(array, size);

	printf("============1 task============\n");
	sortDescending(array, size);
	printArr(array, size);

	printf("============2 task============\n");
	sortInRange(array, size, start, end);
	printArr(array, size);

	printf("============3 task============\na)");
	evenFirst(array, size);
	printArr(array, size);
	printf("b)");
	evenFirst2(array, size);
	printArr(array, size);

	printf("============4 task============\n");
	flag(array, size) > 0 ? printf("Massive is sorted\n") : printf(
			"Massive is unsorted\n");
	search(array, size, number) >= 0 ? printf("Index of number = %d\n", search(
			array, size, number)) : printf("Number %d is not in massive\n",
			number);

	return 0;
}

int search(int arr[], int size, int number) {
	int left = 0, right = size - 1, middle, index = -1;
	if (flag(arr, size) == 1) {
		while (left <= right) {
			middle = (left + right) / 2;
			if (arr[middle] == number) {
				index = middle;
				break;
			}
			if (number < arr[middle]) {
				right = middle - 1;
			} else {
				left = middle + 1;
			}
		}
	} else if (flag(arr, size) == 2) {
		while (left <= right) {
			middle = (left + right) / 2;
			if (arr[middle] == number) {
				index = middle;
				break;
			}
			if (number < arr[middle]) {
				left = middle + 1;
			} else {
				right = middle - 1;
			}
		}
	} else {
		int i;
		for (i = 0; i < size; i++) {
			if (arr[i] == number)
				index = i;
		}
	}
	return index;

}

int flag(int arr[], int size) {
	int i, countUp = 0, countDown = 0;
	for (i = 1; i < size; i++) {
		if (arr[i - 1] <= arr[i])
			countUp++;
		if (arr[i - 1] >= arr[i])
			countDown++;
	}
	if (countUp == size - 1)
		return 1; //по возрастающей
	else if (countDown == size - 1)
		return 2; //по убывающей
	else
		return 0; //не отсортирован
}

void evenFirst2(int ar[], int size) {
	int i, j, min, minIndex;
	for (i = 0; i < size; i++) {
		min = ar[i];
		minIndex = i;
		for (j = i + 1; j < size; j++) {
			if (ar[j] % 2 == 0 && ar[j] < min) {
				min = ar[j];
				minIndex = j;
			}
		}
		if (i != minIndex) {
			swap(ar, size, i, minIndex);
		}
	}
}

void evenFirst(int ar[], int size) {
	int i, j, min, minIndex;
	for (i = 0; i < size; i++) {
		min = ar[i];
		minIndex = i;
		for (j = i + 1; j < size; j++) {
			if (ar[j] % 2 == 0) {
				min = ar[j];
				minIndex = j;
			}
		}
		if (i != minIndex) {
			swap(ar, size, i, minIndex);
		}
	}
}

void sortInRange(int ar[], int size, int start, int end) {
	int i, j, min, minIndex;
	if (start > end || start < 0 || end > size - 1) {
		printf("Invalid value, massive without changes\n");
	} else {
		for (i = start; i <= end; i++) {
			min = ar[i];
			minIndex = i;
			for (j = i + 1; j <= end; j++) {
				if (ar[j] < min) {
					min = ar[j];
					minIndex = j;
				}
			}
			if (i != minIndex) {
				swap(ar, size, i, minIndex);
			}
		}
	}
}

void sortDescending(int ar[], int size) {
	int i, j, max, maxIndex;
	for (i = 0; i < size; i++) {
		max = ar[i];
		maxIndex = i;
		for (j = i + 1; j < size; j++) {
			if (ar[j] > max) {
				max = ar[j];
				maxIndex = j;
			}
		}
		if (i != maxIndex) {
			swap(ar, size, i, maxIndex);
		}
	}
}

void swap(int arr[], int size, int i, int j) {
	int temp = arr[i];
	arr[i] = arr[j];
	arr[j] = temp;
}

void fillArrayRange(int arr[], int size, int from, int to) {
	srand(time(NULL));
	int i;
	for (i = 0; i < size; i++) {
		arr[i] = from + rand() % (to + 1 - from);
	}
}

void printArr(int ar[], int size) {
	int i;
	for (i = 0; i < size; i++) {
		printf("%d ", ar[i]);
	}
	printf("\n");
}