Fixing Puzzle Game - puzzle

Question

I'm new to C++ and programming in general, and this is my first 'project'. I'm sorry if this is not an applicable question, tell me and I will delete it right away.
I want to build a puzzle game, but instead of sliding tiles, the user swaps the number adjacent to '0', where '0' is the blank tile.
This is the code I've so far:
#include <iostream>
#include <ctime>
#include <algorithm>
using namespace std;
int grid[]= {1,2,3,4,5,6,7,8,0};
void shuffle()
{
random_shuffle(&grid[0],&grid[9]);
}
void print_puzzle()
{
shuffle();
int a=grid[0];
int b=grid[1];
int c=grid[2];
int d=grid[3];
int e=grid[4];
int f=grid[5];
int g=grid[6];
int h=grid[7];
int i=grid[8];
cout<<endl;
cout<<" "<<a<<" "<<b<<" "<<c<<endl;
cout<<" "<<d<<" "<<e<<" "<<f<<endl;
cout<<" "<<g<<" "<<h<<" "<<i<<endl;
}
bool check()
{
if (grid[0]==1&&grid[1]==2&&grid[2]==3&&grid[3]==4&&grid[4]==5&&grid[6]==7&&grid[7]==8&&grid[8]==0)
{
return true;
}
else
{
return false;
}
}
void swap_puzzle()
{
print_puzzle();
int temp=0;
cout<<"Enter the number adjacent to '0' that you want to be swapped with '0'."<<endl;
cin>> temp;
while(check==false)
{
for(int i=0; i<9; i++)
{
if(grid[i]==temp)
{
int pos_num=i;
for(int j=0; j<9; j++)
{
if(grid[j]==0)
{
int pos_0=j;
swap(grid[pos_num], grid[pos_0]);
break;
}
}
}
}
print_puzzle();
}
}
int main()
{
srand ( time(NULL) );
cout<<"The Rules:"<<endl;
cout<<"There will be a shuffled 3x3 grid with numbers from 1-8, with one blank space denoted by '0'. You can swap '0' only with adjacent numbers. The goal of this game is to rearrange the numbers in the grid in ascending order."<<endl;
cout<<endl;
cout<<"The Shuffled Grid: "<<endl;
swap_puzzle();
return 0;
}
After swapping the number that the enter user with '0', the grid just shuffles instead of swapping them as I intended. I tried fixing this problem by breaking the code into smaller functions, but that didn't help.
Any advice would be appreciated.

Answer 1

Your code has several problems.
At the end of your swap_puzzle() function, inside the while loop, you call print_puzzle(). print_puzzle calls shuffle(). That's why everything is shuffled instead of having just a swap operation. To fix this you must decouple these 2 functions: printing is one thing, shuffling is another one. Neither of these should trigger the other. Or MAYBE you could have the shuffle function that calls the print one at the end, to show the new status; but a "print" function should never do anything other than printing.
Then, in your check() function you have forgotten grid[5]==6. Actually this might not be important, because if all the others are at the right place, then grid[5] should automatically be right. Anyway, for what it costs, I would definitely add it.
Then, your swap_puzzle() has a problem where you call swap and then you break. You have 2 nested for loops, and you must break from both. Right now, you are breaking from the inner one (the one that uses j), which means that then the program will resume at the next iteration of i. It is possible, then, that the swap conditions are met again, as a result of the previous swap. So the user wants to make one move, and he ends up with 2. To be precise, the second one will revert the first one, and of course this is not wanted. To solve this you could add a bool variable called swapped and set it to false at the beginning of the while loop; when you reach the break, before breaking you set it to true. Then, immediately after the end of the inner loop, you check the value of swapped: if it is true you have to break again.
As your program is structured right now, you display cout and read the input with cin only once. You must put both functions inside the while loop, so that they are run every time, for every move.

Answer 2

In your print_puzzle function you have this line
shuffle();
That mean every time you go to print your puzzle, it shuffles it. You don't want that.
Also this line:
while(check==false)
should be
while(check()==false)
check by itself is the pointer to the function, not a call to the function.
You also want to move the request for a new number to swap inside your loop, otherwise your loop will just go on forever.

Answer 3

I did some minor changes and it works.
starting game may need to shuffle once.
call to shuffle() in swap_puzzle() (but don't shuffle it when printing)
put cin>> temp; in the while loop so users can input till puzzle solved
break the inner loop too(i added some vars for that)
finally call to check() and break if true. thats means solved.
--
#include <iostream>
#include <ctime>
#include <algorithm>
using namespace std;
int grid[]= {1,2,3,4,5,6,7,8,0};
void shuffle()
{
random_shuffle(&grid[0],&grid[9]);
}
void print_puzzle()
{
// shuffle();
int a=grid[0];
int b=grid[1];
int c=grid[2];
int d=grid[3];
int e=grid[4];
int f=grid[5];
int g=grid[6];
int h=grid[7];
int i=grid[8];
cout<<endl;
cout<<" "<<a<<" "<<b<<" "<<c<<endl;
cout<<" "<<d<<" "<<e<<" "<<f<<endl;
cout<<" "<<g<<" "<<h<<" "<<i<<endl;
}
bool check()
{
if (grid[0]==1&&grid[1]==2&&grid[2]==3&&grid[3]==4&&grid[4]==5&&grid[6]==7&&grid[7]==8&&grid[8]==0)
{
return true;
}
else
{
return false;
}
}
void swap_puzzle()
{
shuffle();
print_puzzle();
int temp=0;
bool swaped = false;
while(1)
{
swaped = false;
cout<<"Enter the number adjacent to '0' that you want to be swapped with '0'."<<endl;
cin>> temp;
for(int i=0; i<9; i++)
{
if(grid[i]==temp)
{
int pos_num=i;
for(int j=0; j<9; j++)
{
if(grid[j]==0)
{
int pos_0=j;
swap(grid[pos_num], grid[pos_0]);
swaped = true;
break;
}
}
}
if(swaped) break;
}
print_puzzle();
if(check()==true) break;
}
}
int main()
{
srand ( time(NULL) );
cout<<"The Rules:"<<endl;
cout<<"There will be a shuffled 3x3 grid with numbers from 1-8, with one blank space denoted by '0'. You can swap '0' only with adjacent numbers. The goal of this game is to rearrange the numbers in the grid in ascending order."<<endl;
cout<<endl;
cout<<"The Shuffled Grid: "<<endl;
swap_puzzle();
return 0;
}