<Codesignal> All Longest Strings

Easy

Given an array of strings, return another array containing all of its longest strings.

Example

For inputArray = ["aba", "aa", "ad", "vcd", "aba"], the output should be
allLongestStrings(inputArray) = ["aba", "vcd", "aba"].

Input/Output

• [execution time limit] 0.5 seconds (c)

• [input] array.string inputArray

  A non-empty array.

  Guaranteed constraints:
  1 ≤ inputArray.length ≤ 10,
  1 ≤ inputArray[i].length ≤ 10.

• [output] array.string

  • Array of the longest strings, stored in the same order as in the inputArray.

[C] Syntax Tips

/ Prints help message to the console
// Returns a string
char * helloWorld(char * name) {
    char * answer = malloc(strlen(name) + 8);
    printf("This prints to the console when you Run Tests");
    strcpy(answer, "Hello, ");
    strcat(answer, name);
    return answer;
}

---

Solution

// Arrays are already defined with this interface:
// typedef struct arr_##name {
//   int size;
//   type *arr;
// } arr_##name;
//
// arr_##name alloc_arr_##name(int len) {
//   arr_##name a = {len, len > 0 ? malloc(sizeof(type) * len) : NULL};
//   return a;
// }
//
//
arr_string allLongestStrings(arr_string inputArray)
{
	arr_string returnStrings;
	int max=0, count=0;

	for(int i=0;i<inputArray.size;i++)
		max=strlen(inputArray.arr[i])>max?strlen(inputArray.arr[i]):max;
	for(int i=0;i<inputArray.size;i++)
		count+=strlen(inputArray.arr[i])==max;

	returnStrings=alloc_arr_string(count);
	for(int i=0;i<returnStrings.size;i++)
		returnStrings.arr[i]=malloc((max+1)*sizeof(char));

	for(int i=inputArray.size-1;i>=0;i--)
		if(strlen(inputArray.arr[i])==max)
			strcpy(returnStrings.arr[--count],inputArray.arr[i]);

	return returnStrings;
}