Remove/Add nvidia drivers ubuntu 14.04.2

Question

I'm trying to populate a blank 2d array (matrix) with a character D put onto a random position.

This is the code which works properly:

#define RIGHE 10
#define COLONNE 10

void drawMap(char[][COLONNE]);

int main()
{
    char mappa[RIGHE][COLONNE] = {" "}; // blank, as an empty chess board

    drawMap(mappa);

    return 0;

}

/* Disegna la mappa da gioco */
void drawMap(char mappa[][COLONNE])
{
    int rigaDestinazione, colonnaDestinazione;

    srand(time(NULL)); // Randomizza numeri

    rigaDestinazione = rand() % RIGHE;
    colonnaDestinazione = rand() % COLONNE;

    mappa[rigaDestinazione][colonnaDestinazione] = 'D';

    for (int i = 0; i < RIGHE; i++) {
        for (int j = 0; j < RIGHE; j++) {
            printf("[ %c ]", mappa[i][j]);     
        }
        printf("\n");
    }

}

Unfortunately when I print it, it seems to be asymmetric as you can see, the output is:

[   ][  ][  ][  ][  ][  ][  ][  ][  ][  ]
[  ][  ][  ][  ][  ][  ][  ][  ][  ][  ]
[  ][  ][  ][  ][  ][  ][  ][  ][  ][  ]
[  ][  ][  ][  ][  ][  ][  ][  ][  ][  ]
[  ][  ][  ][  ][  ][  ][  ][  ][  ][  ]
[  ][  ][  ][  ][  ][  ][  ][  ][  ][  ]
[  ][  ][  ][  ][  ][  ][  ][  ][  ][  ]
[  ][  ][  ][  ][ D ][  ][  ][  ][  ][  ]
[  ][  ][  ][  ][  ][  ][  ][  ][  ][  ]
[  ][  ][  ][  ][  ][  ][  ][  ][  ][  ]

How can I fix?

Solution

Firstly,

sudo apt-get remove --purge nvidia*

Enable the Universe and Multiverse repositories - you need to do this to allow the bumblebee and nvidia packages respectively to be installed. Then:

sudo add-apt-repository ppa:bumblebee/stable

sudo apt-get update

sudo apt-get install bumblebee bumblebee-nvidia primus linux-headers-generic

sudo reboot

To run your application with the discrete NVIDIA card run in the terminal:

optirun [options] <application> [application-parameters] 

Example:

optirun firefox 

For a list of options for optirun run:

optirun --help

You can also use prime-select option e.g.

sudo prime-select nvidia

sudo prime-select intel

To check:

prime-select --query

Comments

[Eraklon]

Some quick solution: if (mappa[i][j] != 0) printf("[ %c ]", mappa[i][j]); else printf("[ ]", mappa[i][j]);

[Admin]

Works. Is there another solution without using string.h?

[Ruslan]

@anastaciu sizeof(char) is by definition 1, no need in this tautology. And it's better to let the compiler find out the size automatically by using sizeof mappa instead of doing the calculation manually.

[anastaciu]

@ItsGhost, there is, like Ruslan said, in a loop, you can do it in the loop you already have.

[anastaciu]

@Ruslan, yes, sizeof(mappa) is better.

[anastaciu]

@ItsGhost, glad to help