Question

In C please

After exploring an old shipwreck, you recovered the captain's logs for an old pirate ship. It was stored on an old waterproof USB flash drive. (Who knew pirates were so technologically advanced!). After recovering the data, you see the log is stored as an array of strings:

char* log[] = {
    "Yarr, it be the first day since we set sail.",
    "We be now deep in the seas. Not a soul fer miles.",
    "Blimey! There been movement in the deep today.",
    "It be the kraken! we've battened down the 'atches an' prepared fer battle.",
    "I fear our ship may not 'old much longer. I must 'elp me crew",
    "The beast be winning, but I won't give to the sky without a fight.",
    "We 'ave bested the beast. We gave no quarter. We 'ave won."
};

Remember that you have seen arrays of strings before when working with command line arguments.

We will call this array of strings the log. The example log above contains seven entries (strings).

You will write a function that concatenates the log entries into a single, long string. Each entry should be terminated by a new line:

Yarr, it be the first day since we set sail.
We be now deep in the seas. Not a soul fer miles.
Blimey! There been movement in the deep today.
etc.

Note: the strcat(dest, src) function may be useful in solving this problem.

Your function should have the format:

char* flatten(char* log[], int length) {
}

The function accepts the log and its length (number of entries) as a parameter. It returns a pointer to a single string formatted as described above. The log entries can be any length, and there can be any number of entries, so you must use malloc to dynamically size the single, long string that you will be returning.

The main function is already implemented for you to test the first example. Simply implement the flatten function and return the string pointer for the single, long string. You must include the main function in your submission (provided in the template) so the code will compile. Note that only the return value of the flatten function will be tested.

Answers must be exact with the proper number of \ns.

Examples

Example 1

Given log is:

char* log[] = {
    "abc",
    "words words words",
    "this is another line of text. more words here.",
    "this is the fourth line"
};

If you call:

char* str = flatten(log, 4);

The expected value of str is:

abc
words words words
this is another line of text. more words here.
this is the fourth line

(there is a \n after each of the four lines)

To be more clear, the string would be exactly:

abc\nwords words words\nthis is another line of text. more words here.\nthis is the fourth line\n

With all four \ns included, including the trailing \n.

Example 2

Given log is:

char* log[] = {
    "I am a sentence. There are words here."
};

If you call:

char* str = flatten(log, 1);

The expected value of str is:

I am a sentence. There are words here.\n

TEMPLATE

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

char* flatten(char* log[], int length) {

// CODE HERE

}

// Example main. You only need to write 'flatten', but this is here to help you test.

int main() {

char *log[] = {"This is line one","I am line two","A third line is here"};

char* str = flatten(log, 3);

printf("%s", str); // No need for \n in printf as the returned string should already have a trailing \n

// Expected output (note the three "\n"s at the end of each line):

/*

This is line one

I am line two

A third line is here

*/

}

Answer 1

If you have any doubts, please give me ocmment...

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

char* flatten(char* log[], int length) {

// CODE HERE

int i, l, s = 0;

for(i=0; i<length; i++)

s += strlen(log[i])+1;

char *str = (char *)malloc(sizeof(char)*s);

s = 0;

for(i=0;i<length; i++){

strcat(str, log[i]);

l = strlen(log[i]);

s += l;

str[s] = '\n';

s++;

}

str[s] = '\0';

return str;

}

// Example main. You only need to write 'flatten', but this is here to help you test.

int main() {

char *log[] = {"This is line one","I am line two","A third line is here"};

char* str = flatten(log, 3);

printf("%s", str); // No need for \n in printf as the returned string should already have a trailing \n

// Expected output (note the three "\n"s at the end of each line):

/*

This is line one

I am line two

A third line is here

*/

}