`luc072.c`¶

Problem Statement

How many bytes in memory would be occupied by the following array of pointers to strings? How many bytes would be required to store the same strings in a two-dimensional character array?

Metadata¶

Property	Detail
Author	Amit Dutta amitdutta4255@gmail.com
Date	08 Feb 2026
License	MIT License (See the LICENSE file for details)
Difficulty	Beginner (index: 0 / 10)

Concepts¶

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Array
Pointers

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Source Code¶

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

int main()
{
    /* Question Analysis:
       char *mess[] = {"Hammer and tongs", "Tooth and nail", "Spit and polish", "You and C"};

       1. Array of Pointers (*mess[]):
          - It stores 4 pointers. 
          - Size of a pointer is typically 4 bytes (32-bit) or 8 bytes (64-bit).
          - Total = 4 * sizeof(char*)
          - Plus the strings themselves are stored elsewhere in memory.

       2. Two-Dimensional Array (mess[][]):
          - Must accommodate the longest string ("Hammer and tongs" = 16 chars + null = 17).
          - Width would be 17 (or more).
          - Size = 4 rows * 17 cols * 1 byte.
    */

    char *mess_ptr[] = {
        "Hammer and tongs", 
        "Tooth and nail", 
        "Spit and polish", 
        "You and C"
    };

    // Longest string length + 1 for null terminator
    // "Hammer and tongs" is 16 chars long.
    char mess_2d[4][17] = {
        "Hammer and tongs", 
        "Tooth and nail", 
        "Spit and polish", 
        "You and C"
    };

    printf("--- Memory Occupation Analysis ---\n\n");

    printf("1. Array of Pointers (char *mess[]):\n");
    printf("   Size of array object itself (4 pointers): %zu bytes\n", sizeof(mess_ptr));
    printf("   (Note: The string literals are stored in read-only memory separately)\n\n");

    printf("2. Two-Dimensional Array (char mess[4][17]):\n");
    printf("   Size of 2D array: %zu bytes\n", sizeof(mess_2d));
    printf("   (Calculation: 4 rows * 17 columns * 1 byte)\n");

    return 0;
}

Explanation¶

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    - Only use the given code. Do NOT assume anything not present.

    - Do NOT add extra examples.

    - Keep explanation clear and short.

    - If something is unclear, say "Not clear from code".

    - Follow the exact format below. Do NOT change headings.

    FORMAT:

    [START]

    ## What it does

    (Explain the overall purpose in 1-2 sentences)

    ## Step-by-step

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    ## Key Concepts

    (List concepts like loop, condition, function, etc.)

    ## Notes

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    [END]

    CODE (luc072.c):

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

    int main()
    {
        /* Question Analysis:
           char *mess[] = {"Hammer and tongs", "Tooth and nail", "Spit and polish", "You and C"};

           1. Array of Pointers (*mess[]):
              - It stores 4 pointers. 
              - Size of a pointer is typically 4 bytes (32-bit) or 8 bytes (64-bit).
              - Total = 4 * sizeof(char*)
              - Plus the strings themselves are stored elsewhere in memory.

           2. Two-Dimensional Array (mess[][]):
              - Must accommodate the longest string ("Hammer and tongs" = 16 chars + null = 17).
              - Width would be 17 (or more).
              - Size = 4 rows * 17 cols * 1 byte.
        */

        char *mess_ptr[] = {
            "Hammer and tongs", 
            "Tooth and nail", 
            "Spit and polish", 
            "You and C"
        };

        // Longest string length + 1 for null terminator
        // "Hammer and tongs" is 16 chars long.
        char mess_2d[4][17] = {
            "Hammer and tongs", 
            "Tooth and nail", 
            "Spit and polish", 
            "You and C"
        };

        printf("--- Memory Occupation Analysis ---\n\n");

        printf("1. Array of Pointers (char *mess[]):\n");
        printf("   Size of array object itself (4 pointers): %zu bytes\n", sizeof(mess_ptr));
        printf("   (Note: The string literals are stored in read-only memory separately)\n\n");

        printf("2. Two-Dimensional Array (char mess[4][17]):\n");
        printf("   Size of 2D array: %zu bytes\n", sizeof(mess_2d));
        printf("   (Calculation: 4 rows * 17 columns * 1 byte)\n");

        return 0;
    }

luc072.c¶