Functional Loop with user input C++ - c++

Question

So I got an assignment to make a program that allows the user to select three favourite destinations in order. It repeats until the user decides to stop. Once the user decides to discontinue, the program then displays the total votes received for each destination according to preference by the users. One user will have three preferences and if the program repeats four times, it means four users’ preferences are recorded. Therefore a total of 12 preferences are recorded in this instance.
I have tried to limit input for the loop to work but it seems it will only work with a decision which is not necessary at the beginning of the program, which i want to remove altogether.
Also, I have tried to limit output for each of the decisions but it will only run once and then move on to the next choice. Is there any way to get a persistent entry prompt that will only continue after a valid input.
Lastly, is there any way I could improve the code by using switch/break statements instead of if/else?
Here's my code:
cout << "Do you want to go forth with this program?\nType y to confirm. The
program will exit if anything else is entered: ";
cin >> Decision;
while (Decision=="y")
{
cout << "\n\nNow please enter the code for which your destination corresponds to: " << endl; //first decision
cin >> Choice1;
if (Choice1 == 1)
{
LasVegas1++;
}
else if (Choice1 == 2)
{
Tokyo1++;
}
if (cin.fail())
{
cout << "Please enter a valid choice" << endl;
continue;
}
cout << " \nNow please enter the second code: " << endl; //second decision
cin >> Choice2;
if (Choice2 == 1)
{
LasVegas2++;
}
else if (Choice2 == 2)
{
Tokyo2++;
}
else
{
cout << "\nError! Please enter a valid code as shown above!\n";
cout << "\nNow please enter the second code: ";
cin >> Choice2;
}
cout << " \nNow please enter the third code: " << endl; //third decsion
cin >> Choice3;
if (Choice3 == 1)
{
LasVegas3++;
}
else
{
cout << "\nError! Please enter a valid code as shown above!\n";
cout << "\nNow please enter the third code: ";
cin >> Choice3;
}
cout << " \nDo you wish to select three more destinations? (Y/N): " << endl;
cin >> Decision;
}

Answer 1

What I would do is to put all your city variables into an array and then convert your three sets of code into a for loop. Something like:
for(int i = 0; i < 3; i++) {
if(Choice1 == 0) {
rome[i]++;
}
//etc
So that way you wouldn't need to repeat the same code three times. Also you only need one Choice variable. (You can just reset it at each iteration of the loop)
Additionally you could implement a switch statement to clean up the code a little:
switch(Choice1) {
case 1:
LasVegas1++;
break;
case 2:
Tokyo1++;
break;
case 3:
London1++;
break;
case 4:
Paris1++;
break;
case 5:
Dubai1++;
break;
case 6:
Mumbai1++;
break;
case 7:
NewYork1++;
break;
case 8:
Sydney1++;
break;
case 9:
Auckland1++;
break;
case 10:
Rome1++;
break;
case 11:
Other1++;
break;
}

Answer 2

It can be heavily simplified by the use of "Switch" and "Break".
Like the code that i have written. Have a look :
char input;
int choice;
void Permission() {
cout << "Do you want to go forth with this program ? (y to confirm)" << flush;
cin >> input;
cout << endl;
}
void Decision1() {
if(input == 'y') {
cout << "Now please enter the code for which your destination corresponds to : " << flush;
cin >> choice;
switch (choice) {
case 1:
cout << "LasVegas " << endl;
break;
case 2:
cout << "Tokyo " << endl;
break;
case 3:
cout << "London " << endl;
break;
case 4:
cout << "Paris " << endl;
break;
case 5:
cout << "Dubai " << endl;
break;
case 6:
cout << "Mumbai " << endl;
break;
case 7:
cout << "New York " << endl;
break;
case 8:
cout << "Sydney " << endl;
break;
case 9:
cout << "Auckland " << endl;
break;
case 10:
cout << "Rome " << endl;
break;
case 11:
cout << "Other " << endl;
break;
default:
cout << "Invalid option. Enter Again : " << flush;
cin >> choice;
}
cout << endl;
}
}
void Decision2() {
cout << "Now please enter the second code: " << flush;
cin >> choice;
switch (choice) {
case 1:
cout << "LasVegas " << endl;
break;
case 2:
cout << "Tokyo " << endl;
break;
case 3:
cout << "London " << endl;
break;
case 4:
cout << "Paris " << endl;
break;
case 5:
cout << "Dubai " << endl;
break;
case 6:
cout << "Mumbai " << endl;
break;
case 7:
cout << "New York " << endl;
break;
case 8:
cout << "Sydney " << endl;
break;
case 9:
cout << "Auckland " << endl;
break;
case 10:
cout << "Rome " << endl;
break;
case 11:
cout << "Other " << endl;
default:
cout << "Invalid option. Enter Again : " << flush;
cin >> choice;
}
cout << endl;
}
void Decision3() {
cout << "Now please enter the third code: " << flush;
cin >> choice;
switch (choice) {
case 1:
cout << "LasVegas " << endl;
break;
case 2:
cout << "Tokyo " << endl;
break;
case 3:
cout << "London " << endl;
break;
case 4:
cout << "Paris " << endl;
break;
case 5:
cout << "Dubai " << endl;
break;
case 6:
cout << "Mumbai " << endl;
break;
case 7:
cout << "New York " << endl;
case 8:
cout << "Sydney " << endl;
break;
case 9:
cout << "Auckland " << endl;
break;
case 10:
cout << "Rome " << endl;
break;
case 11:
cout << "Other " << endl;
break;
default:
cout << "Invalid option. Enter Again : " << flush;
cin >> choice;
}
cout << endl;
}
int main() {
Permission();
Decision1();
Decision2();
Decision3();
system("PAUSE");
return 0;
}
I don't know that how to get the loop at the default when the user enters the wrong option. I was able to give the "cin" once. Update this problem if you know how to.

Answer 3

Yes you could improve with a switch statement. Theres also something called a do while loop you should look into.