pvjc25/du2/program.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <ctype.h>

#define LINE_SIZE 100
#define MAX_COEFFS 100

int is_valid_number(const char *str) {
    char *endptr;
    strtod(str, &endptr);
    return *endptr == '\0' || isspace(*endptr);
}

double horner(double coeffs[], int n, double x) {
    double result = coeffs[0];
    for (int i = 1; i < n; i++) {
        result = result * x + coeffs[i];
    }
    return result;
}

int main() {
    char line[LINE_SIZE];
    double coeffs[MAX_COEFFS];
    int n = 0;


    if (fgets(line, LINE_SIZE, stdin) == NULL || !is_valid_number(line)) {
        fprintf(stderr, "Error: Invalid input for x.\n");
        return 1;
    }
    double x = strtod(line, NULL);


    while (fgets(line, LINE_SIZE, stdin) != NULL && line[0] != '\n') {
        if (!is_valid_number(line)) {
            fprintf(stderr, "Nepodarilo sa nacitat polynom na %d mieste.\n", n + 1);
            return 1; 
        }
        coeffs[n++] = strtod(line, NULL);
    }

    
    double result = horner(coeffs, n, x);
    printf("Vysledok je: %.2f\n", result);

    return 0; 
}