// lab 11

#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <stdbool.h>
#include <locale.h>

void printOnNewLine(char src[]) {
    printf("\n%s", src);
}

void task1() {
    int n,x, power = -1;
    int fact = 1;
    double sum = 0;

    printOnNewLine("Введите x: ");
    scanf("%d", &x);
    printOnNewLine("Введите n: ");
    scanf("%d", &n);

    for (int i=1; i<=n; i++)
    {
        sum += (double) power * x/fact;
        printf("value is %.3lf", (double) power * x/fact);
        power *= -1;
        fact *= i;
    }

    printf("sum is %lf", sum);
}

int calculatePower(int src, int to) {
    int result = src;
    for(int i = 1; i <= to - 1; i++) {
        result *= result;
    }

    return result;
}

void task2() {
    double e;
    int i = 1, x;
    int powerX = 1, power = 2;
    int fact = 1;
    double currentValueOfF = 0, sum = 0;

    printOnNewLine("Введите e: ");
    scanf("%lf", &e);
    printOnNewLine("Введите x: ");
    scanf("%d", &x);

    do
    {
        double divider = (cos(fact)) * i;
        if(divider != 0) {
            currentValueOfF = power / divider;
            sum += currentValueOfF;
        }

        fact *= i;
        powerX *= x;
        power = calculatePower(2, powerX);

    } while (currentValueOfF > e);



    printf("approximate sum is %lf", sum);
}
int main() {
    int numberOfTask = -1;
    do
    {
        printf("\nВведите номер задачи(1, 2 или 3, 0 - для выхода): ");
        scanf("%d", &numberOfTask);

        switch(numberOfTask) {
            case 1: task1(); break;
            case 2: task2(); break;
            default: {
                if (numberOfTask != 0) {
                    printf("\nNumber of task %d doesn't exist!", numberOfTask);
                }
            }
        }
    } while (numberOfTask != 0);

    return 0;
}