<cstdio> fscanf problem

I have some problems with my code, i'm not sure if it's correcty written this is why i am here.
For example, i should get this:

cutie.in :
"
6 2
....XX
X.....
......
..B...
.XXX..
......
S
D
"

cutie.out:
"
....XX
X.....
......
......
.XXX..
B.....
"

#include <fstream>
#include <cstdio>
using namespace std;

FILE * is = fopen("cutie2.in", "r");
FILE * os = fopen("cutie.out", "w");

char a[1001][1001];
int k2, n;
char x;
int bi, bj;
short Direction;


void Read();
void Solve();
void WriteD1();
void WriteD2();
void WriteD3();
void WriteD4();

int main()
{
    Read();
    Solve();
    if (Direction == 1)
        WriteD1();
    if (Direction == 2)
        WriteD2();
    if (Direction == 3)
        WriteD3();
    if (Direction == 4)
        WriteD4();
    fclose(is);
    fclose(os);
    return 0;
}


void Solve()
{
    Direction = 3;
    for (int k = 0; k < k2; k++)
    {
        fscanf(is, "%c", &x);
        int i, j;
        if (x == 'S') Direction++;
        if (x == 'D') Direction--;
        if (Direction == 0) Direction = 4;
        if (Direction == 5) Direction = 1;
        i = bi;
        j = bj;
        if (Direction == 1)
        {
            i--;
            while (a[i][j] ==  '.')
                i--;
            i++;
            a[bi][bj] = '.';
            bi = i;
            bj = j;
            continue;
        }
        if (Direction == 2)
        {
            j++;
            while (a[i][j] ==  '.')
                j++;
            j--;
            a[bi][bj] = '.';
            bi = i;
            bj = j;
            continue;
        }
        if (Direction == 3)
        {
            i++;
            while (a[i][j] ==  '.')
                i++;
            i--;
            a[bi][bj] = '.';
            bi = i;
            bj = j;
            continue;
        }
        if (Direction == 4)
        {
            j--;
            while (a[i][j] ==  '.')
                j--;
            j++;
            a[bi][bj] = '.';
            bi = i;
            bj = j;
            continue;
        }
    }
    a[bi][bj] = 'B';
};

void Read()
{
    fscanf(is, "%d", &n);
    fscanf(is, "%d", &k2);
    for (int i = 1; i <= n; ++i)
        for (int j = 1; j <= n; ++j)
        {
            fscanf(is, "%c", &x);
            a[i][j] = x;
            if (a[i][j] == 'B') bi = i, bj = j;
        }
};


void WriteD1()
{
    for (int i = n; i > 0; --i)
    {
        for (int j = n; j > 0; --j)
        {
            fprintf(os, "%c", a[i][j]);
        }
        fprintf(os, "\n");
    }
};

void WriteD2()
{
    for (int i = 1; i <= n; ++i)
    {
        for (int j = n; j > 0; --j)
        {
            fprintf(os, "%c", a[j][i]);
        }
        fprintf(os, "\n");
    }
};

void WriteD3()
{
    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= n; ++j)
        {
            fprintf(os, "%c", a[i][j]);
        }
        fprintf(os, "\n");
    }
};

void WriteD4()
{
    for (int i = n; i > 0; --i)
    {
        for (int j = 1; j <= n; ++j)
        {
            fprintf(os, "%c", a[j][i]);
        }
        fprintf(os, "\n");
    }
};

closed account (o3hC5Di1)

Hi there,

As this is a C++ forum, and you're including <fstream> anyway, I would suggest using the c++ way of handling file I/O: http://www.cplusplus.com/doc/tutorial/files/

As for your problem, I'm not sure I understand your question. Could you please be a little more specific about what is not working correctly?

All the best,
NwN

Last edited on

vladpotra (4)

Hey, thanks for the answer

I prefer fstream instead of cstdio, but this time, it seems i am forced to use cstdio.

I did a side by side comparison on my <fstream> code and the one with <cstdio> (<fstream> code works perfect, but doesn't fit int the time limit of 0.5 seconds, restrictions : n <= 1000, k2 <= 500000), the writing(fprintf) works just fine, but the reading(void Read(), most likely in the second for, at the char variables AND in void Solve(), at the char reading) has some problems, i don't know whats wrong, i should get this
"
....XX
X.....
......
......
.XXX..
B.....
"
but i get this thing:
"
....X
X
X...
..
...
...
..
B...
.
XXX..
"
which is totally wierd.

For example, even for the writing i found improvements in time. With fstream i got about 0.709s and with cstdio 0.574.

vladpotra (4)

HELP PLS

cire (8284)

On line 108, use: fscanf(is, " %c", &x);. Note the space before the %c which indicates the call should ignore whitespace.

vladpotra (4)

omg dude, you're a sick genius MAN!! YOU DID IT MAN YOU DID ITTTT!!!
FINALLY SOMEONE FOUND THE MISTAKE!!!

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<cstdio> fscanf problem