プログラマ専用SNS ミクプラ

コード:

#include <stdio.h>   // printf, fopen, fclose, fscanf, fprintf
#include <stdlib.h>  // malloc, srand, rand
#include <time.h>    // time

#define SAVEFILE "save.txt"

struct LIST {
    struct LIST *next;
    int value;
};

struct LIST *plist = NULL;

int main(void)
{
    FILE *fp = fopen(SAVEFILE, "r");
    srand((unsigned)time(NULL));

    while (1) {
        int random = 0;
        if (fp && fscanf(fp, "%d", &random) != 1) {
            fclose(fp);
            fp = NULL;
        }
        if (!fp) {
            int q = getchar();
            if (q == 'q') break;
            if (q != '\n') continue;
            random = rand() % 1000;
            if (random < 100) random += 100;
        }

        struct LIST *p = (struct LIST *) malloc(sizeof(struct LIST));
        p->value = random;
        p->next = NULL;

        if (plist == NULL)
            plist = p;
        else {
            struct LIST *prev = plist;
            while (prev->next != NULL) prev = prev->next;
            prev->next = p;
        }
        if (!fp) printf(" %d\n", p->value);
    }

    fp = fopen(SAVEFILE, "w");
    struct LIST *p = plist;
    while (p != NULL) {
        if (fp) fprintf(fp, "%d\n", p->value);
        printf("\n%d", p->value);
        p = p->next;
    }
    if (fp) fclose(fp);

    getchar();
    getchar();
    return 0;
}