Working with vectors and loops - c++

Question

sorry to post a student question here. I'm not looking for a quick solution, I'm looking to understand. Comments in my code will explain the same, but here's a plain text version:
This is the beginning of a "LoShu Magic Square", I'm not to the addition of all parts of the matrix I'm making, I'm stuck at trying to verify that the same number has not been put into the rows before. My idea was to use one vector to "test" numbers that had been entered so far, so it does not need to be multi-dimensional (none of them are, but I don't care about the limit on the tester).
As-is the code will take the first number into the test vector, go to the check function, realize that number is there (which it should, haven't hashed out where to add the initial value), and after that initial check it will take ANY other value between 1-9, including repeats, which is bad. Help please? Why does it stop recognizing values inside the test vector after the initial round?
Separate link to code if it's maybe easier to read there: http://ideone.com/Dzh4mJ
#include<iostream> // This is the beginning of a "LoShu magic square" program for class, currently my
#include <vector> // goal is simply getting vectors to check whether or not a number has already been
using namespace std; // entered, and if so to go back and ask for another one. As-is it does not work
// through the first iteration. It recognizes the first number, says it's already in
bool theCheckening(vector<int>, int ); // and proceeds to take ANY numbers afterwards, repeats and all.
int main () {
int tester;
vector<int> loShu1; // Rows 1-3 of a "square"
vector<int> loShu2;
vector<int> loShu3;
vector<int> testCaseOut(1,0); // Test vector to iterate inside check function
do {
do{
cout << "Enter 1-9: "; // Working as intended, makes sure no number besides 1-9 is entered
cin >> tester;
} while (tester < 1 || tester > 9);
// Put initial value into test Vector
if (theCheckening(testCaseOut, tester)){ // If check function returns true, add value to row 1
loShu1.push_back(tester);
testCaseOut.push_back(tester);
cout << "It worked?!";
}
} while (loShu1.size() <= 2); // shooting for size of 3, working as intended
for (int var : loShu1) // Debug to see rows before maths and adding them (to come)
cout << var << " ";
cout << "\n";
for (int var : loShu2)
cout << var << " ";
cout << "\n";
for (int var : loShu3)
cout << var << " ";
return 0;
}
bool theCheckening(vector<int> testCaseInc, int testInt) {
int count;
vector<int> testCase(testCaseInc); // Initialize vector inside check function to current test numbers
for (int var : testCase)
cout << var << " ";
for (count = 0;count<=testCase.size();count++) { // for all the numbers inside the testing vector
if (testCase[count]!=testInt){ // if current position of test vector is ! in vector already,
cout << "ADDED!"; // add it to row back in main()
return true;
for (int var : testCase)
cout << var << " ";
}
cout << "ALREADY ENTERED!"; // Debug
cout << testCase.size();
return false; // otherwise, ignore and ask for another number
}
}

Answer 1

i think you have a logical error in your theCheckening function.
As far as i understand you want your function to return TRUE if the value is NOT in in the vector and FALSE if it IS in your vector.
Now to the problem:
Imagine someone has tipped in the following values to your code:
1 2 5 8
This values will be added to your vector and the vector will also contain:
1 2 5 8
Now let's say you tipp one more time the 2. Your Function will now start with value 1 of the vector and compare it to the 2. This is of course FALSE.
Look at your code:
if (testCase[count]!=testInt)
return true;
Your code says you can now return true. Which will cause your function to end and return true to the caller.
You didn't check the following values of the vector.
Your function theCheckening should look like this:
// user const vector<int> &, which will not cause to copy the
// vector
bool theCheckening(const vector<int> & testCase, int testInt) {
// use size_t which represents a integer datatype which
// is as big as arrays can be in the current bit setting
// 32 bit => size_t = unsigned int
// 64 bit => size_t = unsigned long long
for(size_t count = 0; count <= testCase.size(); count++) {
if(testCase[i] == testInt)
return false;
}
return true;
}
I hope this works and i understood this qestion correctly.