read_tripletでダブレットを解放する必要がありますか？どうすればいいのですか？

Question

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

static char *ones[] = { 
    "", 
    "one", 
    "two", 
    "three", 
    "four", 
    "five", 
    "six", 
    "seven", 
    "eight", 
    "nine" 
}; 

static char *teens[] = { 
    "", 
    "eleven", 
    "twelve", 
    "thirteen", 
    "forteen", 
    "fifteen", 
    "sixteen", 
    "seventeen", 
    "eighteen", 
    "nineteen" 
}; 

static char *tens[] = { 
    "", 
    "ten", 
    "twenty", 
    "thirty", 
    "forty", 
    "fifty", 
    "sixty", 
    "seventy", 
    "eighty", 
    "ninety" 
}; 

static char *powers[] = { 
    "thousand", 
    "million", 
    "billion", 
    "trillion", 
    "quadrillion", 
    "quintillion", 
    "sextillion", 
    "septillion", 
    "octillion", 
    "nonillion", 
    "decillion" 
}; 

char** read_doublet(int a, int b) { 
    char** doublet = malloc(2 * sizeof (char*)); 
    if (doublet != NULL) { 
     if (a == 0 && b > 0) { 
      doublet[0] = ones[0]; 
      doublet[1] = ones[b]; 
     } else if (a == 1 && b > 0) { 
      doublet[0] = teens[0]; 
      doublet[1] = teens[b]; 
     } else if (a > 0 && b == 0) { 
      doublet[0] = tens[0]; 
      doublet[1] = tens[a]; 
     } else if (a > 0 && b > 0) { 
      doublet[0] = tens[a]; 
      doublet[1] = ones[b]; 
     } else { 
      doublet[0] = ones[0]; 
      doublet[1] = ones[0]; 
     } 
     return doublet; 
    } 
    return NULL; 
} 

char** read_triplet(int a, int b, int c) { 
    char** triplet = malloc(3 * sizeof(char*)); 
    if(triplet != NULL) { 
     triplet[0] = ones[0]; 

     if(a > 0) { 
      triplet[0] = ones[a]; 
     } 

     char** doublet = read_doublet(b, c); 
     if(doublet != NULL) { 
      triplet[1] = doublet[0]; 
      triplet[2] = doublet[1]; 
     } 

     return triplet; 
    } 

    return NULL; 
} 

int main(void) { 
    printf("%s %s %s %s\n", teens[1], ones[1], tens[1], powers[1]); 

    char** answer = read_triplet(2, 1, 2); 
    if (answer != NULL) { 
     printf("%s %s %s", answer[0], answer[1], answer[2]); 
     free(answer); 
    } 
    return (EXIT_SUCCESS); 
} 

上記のコードでは、read_tripletで、ダブレット内のポインタをトリプレットにコピーします。参照カウントまたはガベージコレクタライブラリを使用せずに、メインからダブレットメモリを解放するにはどうすればよいですか？

Answer 1

コードを書くのは良いパターンではないと思います。

char** read_triplet(int a, int b, int c) { 
    char** triplet = malloc(2 * sizeof(char*)); 
    if(triplet != NULL) { 
     triplet[0] = ones[0]; 

     if(a > 0) { 
      triplet[0] = ones[a]; 
     } 

     char** doublet = read_doublet(b, c); 
     if(doublet != NULL) { 
      triplet[1] = doublet; 
     } 

     return triplet; 
    } 

    return NULL; 
} 

int main(void) { 
    printf("%s %s %s %s\n", teens[1], ones[1], tens[1], powers[1]); 

    char** answer = read_triplet(2, 1, 2); 
    if (answer != NULL) { 
     printf("%s %s %s", answer[0], answer[1][0], answer[1][1]); 
     free(answer[1]) 
     free(answer); 
    } 
    return (EXIT_SUCCESS); 
}