使用字符串向量时 C++ 中的分段错误

Question

My code is for an online coding practice site, I have been doing many of the challenges but I cannot seem to get around the segmentation fault error on this one.

The aim of the code is to find the longest length strings in a string vector (up to 10 strings long) and then to return a string vector containing just those longest strings in order.

I believe logically my code works, but I can't test it. I am still new to vectors so can't seem to properly understand other answers on here in relation to my issue.

vector<string> allLongestStrings(vector<string> inputArray) {

    vector<string> longestStrings;            // vector
    int longest_size = longestStrings.size(); // int
    int longestArrayCounter = 0;              // int. For filling longestStrings whenever 
                                              //  there is a long string
    int longest_string = 0;                   // int. For recording the size of the longest string

    for (int i = 0; i < inputArray.size(); i++) {  
        // Loop will:  
        //1. Measure size of string in input array 
        //2. if longest will change value of longest_string and clear longestStrings
        //3. If the same length as longest_string will add it to longestStrings vector
        //4. if it is shorter it will be ignored
       if (inputArray[i].size() > longest_string) { // input vector
          longest_string = inputArray[i].size();     // vector

       longestStrings.clear(); //clearing the vector to only store longest string values
       longestArrayCounter = 0; //reset counter for longestStrings
       longestStrings[longestArrayCounter++] = inputArray[i];//puts new longest string from input into my vector
       }

       if (inputArray[i].size() == longest_string) { 
       longestStrings[longestArrayCounter++] =inputArray[i];// my vector and input vector
       }
   }
   return longestStrings;
}

Answer 1

       longestStrings.clear();
       longestArrayCounter = 0;
       longestStrings[longestArrayCounter++] = inputArray[i];

is bad because you are doing assignment to non-existent element.

Instead of the two

longestStrings[longestArrayCounter++] = inputArray[i];

you should do

longestStrings.push_back(inputArray[i]);

Then, std::vector will manage the size for you, so you don't have to manage longestArrayCounter by yourself. Use longestStrings.size() to obtain the size.