pvjc25/du3/program.c

143 lines
3.0 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <ctype.h>
#define EPSILON 0.001
void trim_newline(char *line) {
size_t len = strlen(line);
if (len > 0 && line[len - 1] == '\n') {
line[len - 1] = '\0';
}
}
char* skip_spaces(char *str) {
while (*str && isspace((unsigned char)*str)) {
str++;
}
return str;
}
int parse_expression(char *line, float *num1, char *op, float *num2, float *result) {
char *ptr = line;
ptr = skip_spaces(ptr);
char *endPtr;
*num1 = strtof(ptr, &endPtr);
if (ptr == endPtr) {
return 1;
}
ptr = endPtr;
ptr = skip_spaces(ptr);
if (*ptr == '\0') return 1;
*op = *ptr;
if (*op != '+' && *op != '-' && *op != '*' && *op != '/') {
return 1;
}
ptr++;
ptr = skip_spaces(ptr);
*num2 = strtof(ptr, &endPtr);
if (ptr == endPtr) {
return 1;
}
ptr = endPtr;
ptr = skip_spaces(ptr);
if (*ptr != '=') {
return 1;
}
ptr++;
ptr = skip_spaces(ptr);
*result = strtof(ptr, &endPtr);
if (ptr == endPtr) {
return 1;
}
ptr = endPtr;
ptr = skip_spaces(ptr);
if (*ptr != '\0') {
return 1;
}
return 0;
}
float calculate(float num1, char op, float num2, int *error) {
*error = 0;
float res;
switch(op) {
case '+':
res = num1 + num2;
break;
case '-':
res = num1 - num2;
break;
case '*':
res = num1 * num2;
break;
case '/':
if (fabs(num2) < EPSILON) {
*error = 1;
return 0;
}
res = num1 / num2;
break;
default:
*error = 1;
return 0;
}
return res;
}
void process_line(const char *line, char *output, size_t output_size) {
char buffer[256];
strncpy(buffer, line, 255);
buffer[255] = '\0';
trim_newline(buffer);
float num1, num2, givenResult;
char op;
if (parse_expression(buffer, &num1, &op, &num2, &givenResult) != 0) {
snprintf(output, output_size, "CHYBA");
return;
}
int calcError = 0;
float calculatedResult = calculate(num1, op, num2, &calcError);
if (calcError) {
snprintf(output, output_size, "ZLE");
return;
}
float roundedResult = round(calculatedResult * 100) / 100;
if (fabs(roundedResult - givenResult) <= EPSILON) {
snprintf(output, output_size, "OK");
} else {
snprintf(output, output_size, "ZLE");
}
}
int main(int argc, char *argv[]) {
char buffer[256];
char output[32];
while (fgets(buffer, sizeof(buffer), stdin) != NULL) {
trim_newline(buffer);
if (*skip_spaces(buffer) == '\0') {
break;
}
process_line(buffer, output, sizeof(output));
printf("%s\n", output);
}
return 0;
}