C++ simple game using a Loop program - c++

Question

This program will play a game with the user, called Odds and Evens. The computer will play Evens, and the human user will play Odds. For a round of the game, each player picks an integer in the range [1,10]. The players pick their numbers independently: neither player knows the other player's number before choosing its own number. If the sum of the numbers is even, then Evens (the computer) wins that round; if the sum of the numbers is odd, then Odds (the human) wins that round. The game continues for as many rounds as the user want to play; the user ends the game by typing a non-# or a number outside [1,10] for the input. At the end of the game, the program summarizes the score.
I am having trouble properly looping this question. Randomizing the number pc chooses is not working as every round in the game the pc chooses the same number. Also i do not know how I would have the program summarize the score. Help would be much appreciated as I have another problem for homework that is similar to this!
Here is my code:
#include <iostream>
#include <cmath>
#include <cstdlib>
#include <string>
#include <iomanip>
#include <ctime>
using namespace std;
bool die(const string & msg);
int main(){
srand(static_cast<unsigned>(time(0)));
unsigned num1 = 0, num = 0, sum = 0;
bool userTurn = true;
cout << "Welcome to the Odds and Evens game!";
num = rand() % 10 + 1;
while (num){
if (userTurn){
cout << " Your # in [1,10] is ";
cin >> num1;
}
else {
cout << "My number is " << num;
sum = num1 + num;
if (sum % 2 == 0){
cout << " I win!";
}
else {
cout << " You win!";
}
}
userTurn = !userTurn;
}
}
bool die(const string & msg){
cout << "Fatal error: " << msg << endl;
exit(EXIT_FAILURE);
}

Answer 1

Randomizing the number pc chooses is not working as every round in the game the pc chooses the same number.
You don't have code to re-set the value of num when it's the computer's turn.
After the line
userTurn = !userTurn;
add
if ( !userTurn )
{
num = rand() % 10 + 1;
}
Also i do not know how I would have the program summarize the score.
Keep two counters that indicate how many times the human won and how many times the computer won.
int computerWinCount = 0;
int humanWinCount = 0;
and then, update the loop to use:
if (sum % 2 == 0){
cout << " I win!";
++computerWinCount;
}
else {
cout << " You win!";
++humanWinCount;
}
The conditional of the while loop is such that your program will never terminate. Update it to something like below.
while (true) {
if (userTurn){
cout << " Your # in [1,10] is ";
cin >> num1;
// If the user entered a number that is not
// within range or the user did not input a number,
// then break out of the loop.
if ( !cin || num1 < 1 || num1 > 10 )
{
break;
}
}
else {
cout << "My number is " << num;
sum = num1 + num;
if (sum % 2 == 0){
cout << " I win!" << endl;
++computerWinCount;
}
else {
cout << " You win!" << endl;
++humanWinCount;
}
}
userTurn = !userTurn;
if ( !userTurn )
{
num = rand() % 10 + 1;
}
}
To report the summary, add the following lines before the end of the main.
cout << "Number of times I won: " << computerWinCount << endl;
cout << "Number of times you won: " << humanWinCount << endl;

Answer 2

Here:
num = rand() % 10 + 1;
while (num){
... // never change num
}
Do you see the problem? The computer player chooses num randomly, but only once. Just put another num = rand() % 10 + 1; inside the main loop.
(Also, you don't seem to have a way for the user to terminate the game.)

Answer 3

So you want a simple loop that will do the following things.
get the user input.
get the computer input
check to see who win's the current round
update scores.
this happens until the user chooses an option not from 1 to 10
after this you want to display the score.
Here is a complete example.
#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;
int main(){
int mynum, compNum, myScore(0), compScore(0);
srand(time(NULL));
cout << "Welcome to the Odds and Evens game!" << endl;
cout << "Your # in [1,10] is ";
while ((cin >> mynum) && mynum > 0 && mynum <= 10){
compNum = rand()%10 + 1;
if ((mynum + compNum)%2){
cout << "You win" << endl;
++myScore;
} else {
cout << "Computer Wins" << endl;
++compScore;
}
cout << "Your # in [1,10] is ";
}
cout << "You won " << myScore << " games" << endl;
cout << "The computer won " << compScore << " games" << endl;
return 0;
}
Your problem with the computer's number not changing is due to the fact you do not update its value within the loop.
If you want to keep track of the score, you can simply keep two integers that keep track of how many times the user has won and how many times the computer has won. Then at the end (after the while loop) cout each of their scores.
Overall your code is pretty close.
You just need to make sure you update the computer's guess inside the while loop and when you decide who's won the round increment that person's score.
The whole loop condition in your original code will always evaluate to true. As num will always be to a number 1 to 10. You'll want to use the user's input in the while loop condition.
The while condition in my code will do the following:
get the user's input. cin >> mynum will evaluate to false if cin fails to read a number. If it did read a number the condition will check to see if the number is between 1 and 10 inclusive.