How to reset std::count return value - c++

Question

std::count returns a value and I need this value to reset to 0 for all characters in the variable 'counter' after executing the inner for loop. Goal is to count how many times a character appears. If this character appears twice in the string, add one to variable 'd'. If it appears three times, add one to variable 'e'.
Not sure what else to try or if there is potentially a better function to achieve my result.
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <cstring>
int main() {
std::string data;
std::vector<std::string> myString;
std::vector<char> myChar;
int d = 0, e = 0;
std::ifstream inFile;
inFile.open("C:\\Users\\Administrator\\Desktop\\c++ files\\input2.txt");
if (!inFile) {
std::cout << "oops";
}
for (int i = 0; i < 1; i++) {
inFile >> data;
std::copy(data.begin(), data.end(), std::back_inserter(myChar)); //copy from string data to vector myChar via back inserter.
char counter = 'a';
for (int i = 0; i < 26; i++) {
int myCount = std::count(myChar.begin(), myChar.end(), counter);
if (myCount == 2) {
d++;
}
else if (myCount == 3) {
e++;
}
std::cout << "Counter : " << counter << " myCount : " << myCount << "\n";
counter++;
}
}
std::cout << "d is: " << d << "\n";
std::cout << "e is: " << e << "\n";
return 0;
}
input file -- https://adventofcode.com/2018/day/2
The program works correctly on first inner for loop, but second and after return values that are too high (albeit correct) for the 'myCount' variable.

Answer 1

std::count doesn't just give you a random value, it gives you a specific value based on the contents of the range you give it. You can't change that behaviour, not should you want to.
Instead, look at that range. Why does std::count gives values that you don't expect? They are either "too high" or they are "correct" and cannot be both; fortunately they are the latter.
This is because you repeatedly std::back_insert to the vector inside your loop. As the loop progresses, you keep counting the old characters from the last time!
If you first cleared myChar then you wouldn't have the problem. Or, ideally, bring the declaration of myChar inside the loop.

Answer 2

A few fixes
1) On error the program should end, not continue:
if (!inFile)
{
std::cout << "oops";
return 1;
}
2) a)myChar is accumulating all the chars of all previously read words, so it has to be cleared before use with every pass of the loop, best to move it's declaration into the block required;
b) if you're using a counter just to count but not using it, better to iterate over the data - in this case get rid of i and iterate with chars checked_char:
while (inFile >> data)
{
std::vector< char > myChar;
std::copy(data.begin(),
data.end(),
std::back_inserter(myChar)); //copy from string data to vector myChar via back inserter.
for (char checked_char = 'a'; checked_char <= 'z'; ++checked_char)
{
int myCount = std::count(myChar.begin(), myChar.end(), checked_char);
if (myCount == 2)
{
d++;
}
else if (myCount == 3)
{
e++;
}
std::cout << "Counter : " << checked_char << " myCount : " << myCount << "\n";
}
}