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

//strchr la tim kiem 1 ki tu trong 1 chuoi
//neu tim thay thi tra ve sai

int isString(char s[]) {
    char regex[] = "@!#{}[])($%^&*";//thich k cho cai nao ki tu nao thi cho vao day
    for (int i = 0; i < strlen(regex); i++) {
        char* find = strchr(s, regex[i]);
        if (find != NULL) {
            printf("Do not allow enter special characters, Please re-input\n");
            return 0;
        }
    }
    return 1;
}

//cat 1 choi ra mang 2 chieu khong bao gom dau cach

void split(char arr[][40], int &size, char s[]) {
    char *stok;
    size = 0;
    stok = strtok(s, " ");
    //tim dau cach de cat tat ca ca tu giong voi split trong java
    while (stok != NULL) {
        strcpy(arr[size++], stok);
        stok = strtok(NULL, " ");
        //khoi tao tiep cho bien chat
    }
}

//noi cac tu rieng biet thanh 1 string co dau cach

void rebuild(char arr[][40], int size, char s[]) {
    char temp[40] = "";
    for (int i = 0; i < size - 1; i++) {
        strcat(temp, arr[i]);
        strcat(temp, " ");
    }
    strcat(temp, arr[size - 1]);
    strcpy(s, "");
    strcpy(s, temp);
}

int isContinue() {
    char tmp;
    fpurge(stdin);
    printf("\nDo you want continue(press 0 exit): ");
    scanf("%c", &tmp);
    if (tmp == '0') {
        return 1;
    } else {
        return 0;
    }
}

int main() {
    char string[60];
    char arr[30][40];
    int size = 0;
    do {
        do {
            fpurge(stdin);
            printf("Enter a string: ");
            gets(string);
            split(arr, size, string);
            rebuild(arr, size, string);
        } while (!isString(string));
        printf("%s", string);
    } while (!isContinue());

    free(string);
}