50027. File Sorter

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "fs.h"
 
Account tmp;
Account arr[65536];
 
void pt(Account* a){
    printf("%d, %s, %d\n", a->balance, a->name, a->gender);
}
 
int check_balance(int balance){
    return balance >= 0;
}
int check_name(char* name){
    int n = strlen(name);
    for(int i = 0; i < n; i++){
        if(!(isalpha(name[i])) && (name[i] != ' ')) return 0;
    }
    return 1;
}
int check_gender(int gender){
    return (gender == 0) || (gender == 1);
}
 
int check_valid(Account* a){
    return check_balance(a->balance) && check_name(a->name) && check_gender(a->gender);
}
 
int cmp(const void* a, const void *b){
    Account* act_a = (Account*)a;
    Account* act_b = (Account*)b;
 
    return strcmp(act_a->name, act_b->name);
}
 
 
int main(){
    char in_dir[256], out_dir[256];
    scanf("%s %s", in_dir, out_dir);
 
    FILE* f_in = fopen(in_dir, "rb");
    FILE* f_out = fopen(out_dir, "wb");
 
    int n = 0;
    while(fread(&tmp, sizeof(Account), 1, f_in)){
        if(check_valid(&tmp)) arr[n++] = tmp;
    }
    qsort(arr, n, sizeof(Account), cmp);
    fwrite(arr, sizeof(Account), n, f_out);
 
    fclose(f_in);
    fclose(f_out);
    return 0;
}