Solve C++ "Simon Says" Memory Game with a for Loop

[ineedhelpnow]

"Simon Says" is a memory game where "Simon" outputs a sequence of 10 characters (R, G, B, Y) and the user must repeat the sequence. Create a for loop that compares the two strings starting from index 0. For each match, add one point to userScore. Upon a mismatch, exit the loop using a break statement. Ex: The following patterns yield a userScore of 4:

simonPattern: R, R, G, B, R, Y, Y, B, G, Y
userPattern: R, R, G, B, B, R, Y, B, G, Y
Sample program:

#include <iostream>
#include <string>
using namespace std;

int main() {
   string simonPattern;
   string userPattern;
   int userScore = 0;
   int i = 0;
   
   userScore = 0;
   simonPattern = "RRGBRYYBGY";
   userPattern  = "RRGBBRYBGY";

   <STUDENT CODE>

   cout << "userScore: " << userScore << endl;

   return 0;
}

having trouble understanding this activity (Wasntme) can someone like clarify and help me out with it?

 

[MarkFL]

You want to compare the two pattern strings character by character (a looping construct would be appropriate with $i$ as the counter or index), and then if the corresponding characters in the two strings are equal, you want to continue, otherwise you want to quit. Then the score will be calculated from the value of $i$ when the loop finished. So, it sounds like an if-else statement will be needed inside the loop.

Can you make an attempt based on this?

 

[johng1]

Hi,
Rephrase your problem. Given two strings s1 and s2 of the same length l, find the first index i with s1 unequal to s2 or if no such i exists, set i=l. Since C++ strings "start" at index 0 and s1[l]==s2[l]=='\0', this solves your problem.

Student code without a break in the program:

while(i<10 && simonPattern[i]==userPattern[i]) {
   i++;
}

Now modify the while loop with an if statement in the body that uses break. You'll also want to change the "boolean" control expression of the while loop.

This is an example showing that break is never necessary, but break is merely a programmer convenience.

Oops. Sorry, I didn't see that the problem asks to use a for loop; also I didn't notice the use of the string class, but was thinking of C strings. My comment about break was really the reason I replied in the first place.

 

[Evgeny.Makarov]

Since C++ strings "start" at index 0 and s1[l]==s2[l]=='\0', this solves your problem.

C++ strings (objects of class [m]string[/m]) don't have to be null-terminated and may contain '\0' in the middle.

Student code without a break in the program:

while(i<10 && simonPattern[i]==userPattern[i]) {
   i++;
}

The problem asks to write a [m]for[/m] statement, which is more appropriate for loops with a fixed number of iterations. The length of the simonPattern string can be found as [m]simonPattern.size()[/m] or [m]simonPattern.length()[/m].