pvjc20/du5/program.c

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<stdbool.h>
#include<inttypes.h>
#include<errno.h>
#include<ctype.h>

struct Student {
    long pocet_hlasov;
    char meno[256];
};

int compare_students(const void *a, const void *b);
void sort_students(struct Student *students[], int n);
void swap(struct Student **s1, struct Student **s2);

int main() {
    char buffer[512];
    char *retValPtr;
    struct Student *studenti[1000];
    int count = 0;

    while ((retValPtr = fgets(buffer, sizeof(buffer), stdin)) != 0 && feof(stdin) == 0 && ferror(stdin) == 0) {
        long pocet_hlasov;
        char meno[256];
        char *next;

        pocet_hlasov = strtoimax(buffer, &next, 10);

        if (errno == ERANGE || next == 0 || next == &buffer[0]) {
            break;
        }

        // mame medzeru medzi menom a poctom hlasov?
        if (*next != ' ' || *next == '\n' || *next == '\0') {
            break;
        }

        next++;

        // meno zacina neplatnym znakom alebo nie je zadane
        if (isspace(*next) || *next == '\n' || *next == '\0') {
            break;
        }

        char *ptr_meno = meno;

        while (ptr_meno < (meno + sizeof(meno) - 2)
            && *next != '\n'
            && *next != '\0') {
            *ptr_meno = *next;
            next++;
            ptr_meno++;
        }

        *ptr_meno = '\0';

        struct Student *student = 0;

        // najdeme uz zadaneho studenta s rovnakym menom ak existuje
        for (int i = 0; i < count; i++) {
            struct Student *s = studenti[i];

            if (strcmp(s->meno, meno) == 0) {
                student = s;

                break;
            }
        }

        if (student == 0) {
            student = (struct Student*) malloc(sizeof(struct Student)); // alokujeme miesto pre noveho studenta
            
            strcpy(student->meno, meno);
            student->pocet_hlasov = pocet_hlasov;

            studenti[count] = student;
            count++;
        } else {
            student->pocet_hlasov += pocet_hlasov;
        }
    }

    if (count == 0) {
        puts("Chyba: Nepodarilo sa nacitat ziadny zaznam!");

        return 0;
    }

    // zoradime studentov
    // qsort(studenti, count, sizeof(struct Student*), compare_students);
    sort_students(studenti, count);

    // vypiseme vysledky
    puts("Vysledky:");

    for (int i = 0; i < count; i++) {
        struct Student *student = studenti[i];

        printf("%ld %s\n", student->pocet_hlasov, student->meno);
    }

    // nakoniec treba vycistit neporiadok ktory sme spravili
    for (int i = 0; i < count; i++) {
        free(studenti[i]);
    }

    return 0;
}

int compare_students(const void *a, const void *b) {
    const struct Student *s1 = (struct Student*)a;
    const struct Student *s2 = (struct Student*)b;

    if (s1 == 0 || s2 == 0) {
        return 0;
    }

    if (s1->pocet_hlasov != s2->pocet_hlasov) {
        if (s1->pocet_hlasov < s2->pocet_hlasov) {
            return 1;
        } else {
            return -1;
        }
    }

    return strcmp(s1->meno, s2->meno);
}

void sort_students(struct Student *students[], int n) {
    for (int i = 0; i < n - 1; i++) {
        for (int j = 0; j < n - i - 1; j++) {
            int result = compare_students(students[j], students[j + 1]);

            if (result == 0) {
                continue;
            } else if (result > 0) {
                swap(&students[j], &students[j + 1]);
            }
        }
    }
}

void swap(struct Student **s1, struct Student **s2) {
    struct Student *temp = *s1;
    *s1 = *s2;
    *s2 = temp;
}