idz3

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

double solve(double x) {
    double res = 1;
    double tmp = 1;
    for (int i = 1; i <= 100; ++i) {
        tmp *= x / i;
        res += tmp;
    }
    return res;
}

int main(int argc, char **argv) {
    double x, res;
    if (argc == 0) {
        printf("Please enter one of the possible execution keys: -r, -f, -c\n");
        return 0;
    }
    if (strcmp(argv[1], "-r") == 0) {
        srand(time(0));
        x = rand() % 31;
        clock_t begin = clock();
        res = solve(x);
        clock_t end = clock();
        printf("e^%lf = %lf\n", x, res);
        double time_spent = (double) (end - begin) / CLOCKS_PER_SEC;
        printf("Program execution time: %lf\n", time_spent);
    } else if (strcmp(argv[1], "-c") == 0) {
        scanf("%lf", &x);
        clock_t begin = clock();
        res = solve(x);
        clock_t end = clock();
        printf("%lf\n", res);
        double time_spent = (double) (end - begin) / CLOCKS_PER_SEC;
        printf("Program execution time: %lf\n", time_spent);
    } else if (strcmp(argv[1], "-f") == 0) {
        if (argc != 4) {
            printf("Incorrect input\n");
            return 0;
        }
        FILE *input, *output;
        input = fopen(argv[2], "r");
        output = fopen(argv[3], "w");
        if ((input == NULL) || (output == NULL)) {
            printf("Incorrect input\n");
            return 0;
        }
        fscanf(input, "%lf", &x);
        clock_t begin = clock();
        res = solve(x);
        clock_t end = clock();
        fprintf(output, "%lf\n", res);
        double time_spent = (double) (end - begin) / CLOCKS_PER_SEC;
        printf("Program execution time: %lf\n", time_spent);
        fclose(input);
        fclose(output);
    } else {
        printf("Please enter one of the possible execution keys: -r, -f, -c\n");
    }
    return 0;
}