How to separate a string from a file that contains a sequence of chess rounds?

Question

I need to read a file that will be encoded as the example:

1.e4 e6 2.Nf3 d5 3.Nc3 Nf6 4.e5 Nfd7 5.d4 b6 6.Bd3 Ba6 7.O-O Be7 8.Ne2 Bxd3 9.Qxd3 c5 10.c4 Nc6 11.cxd5 Nb4 12.Qe4 Nxd5 13.Qg4 Kf8 14.Nf4 Nxf4 15.Bxf4 h5 16.Qg3 cxd4 17.Rfd1 Rc8 18.Rxd4 Rc7 19.Rad1 h4 20.Qg4 h3 21.Ng5 Bxg5 22.Bxg5 Qe8 23.R4d3 f6 24.exf6 gxf6 25.Bf4 f5 26.Rxh3 Rxh3 27.Bd6+ Kf7 28.Qxh3 Rc8 29.Qh7+ Kf6 30.Bg3 Rc4 31.Bh4+ 1-0

This is a sequence of chess rounds with the proper movements made by the white and black pieces, respectively, the rounds being separated by the numbers "1.... 2.... 3.... etc". In case, I need to read the file, store the movement performed, validate, and, if correct, go to the next move, otherwise I close my program. Obs the whole round is written in a single line.

My question is how do I build the algorithm to read each movement at a time by storing it in a character array. The code is being written in C.

Solution found:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define TAM 10

int main(int argc, char *argv[]) {
    char branca[TAM], preta[TAM];
    int junk;

    FILE *f = fopen(argv[1], "r");

    memset(branca, 0x0, TAM);
    memset(preta, 0x0, TAM);

    while(fscanf(f, "%d.%s %s", &junk, branca, preta) && !feof(f)){

        printf("BRANCA: %s\n", branca);
        printf("PRETA: %s\n", preta);
        printf("---------------\n");

    }

    fclose(f);
    return 0;
}

Answer 1

Good night.

Well, here’s one of the ways to do it, there are other ways...

In the example below, the reading is done character by character and all the file data will be printed on the screen. In this example, I show you one round per line; to identify your separation, I write one ' n' every two characters of read spaces.

For your need, just write the letters on a pointer using dynamic allocation instead of printing them on the screen. If you want to separate the commands by move instead of round, just remove the if on line 20.

#include <stdio.h>
#include <stdlib.h>

int main()
{
    FILE* jogo;

    printf("Mostrando movimentos...\n");

    jogo = fopen("jogo.txt", "r");

    char c = fgetc(jogo);
    int counter = 0;

    do
    {
        if (c == ' ')
        {
            counter++;
            if (counter % 2 == 0) // Quebra linha a cada 2 espaços em branco
                printf("\n");
        }

        printf("%c", c);
        c = fgetc(jogo);
    } while (c != EOF);


    fclose(jogo);
    return 0;
}

About dynamic allocation, if necessary, you can find more information here: https://www.ime.usp.br/~pf/algorithms/classes/aloca.html