Open last used file

This is a discussion on Open last used file within the C++ Programming forums, part of the General Programming Boards category; Opening the file as an ofstream isn't a good way to see if the file exists. Try ifstream....

  1. #16
    Frequently Quite Prolix dwks's Avatar
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    Opening the file as an ofstream isn't a good way to see if the file exists. Try ifstream.
    dwk

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  2. #17
    Registered User L_U_K_E's Avatar
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    Thanx for the tip.

  3. #18
    Registered User L_U_K_E's Avatar
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    Is there anything like ios::dontreplace(or something or nothing) that i can add somewhere so a same named file will not be deleted and then i can ask them to change the filename???

  4. #19
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    In pre-standard C++, there were ios::nocreate and ios::noreplace, however they don't exist in standard C++ anymore. You should just try opening the file and check yourself.
    Code:
    #include <stdio.h>
    
    void J(char*a){int f,i=0,c='1';for(;a[i]!='0';++i)if(i==81){
    puts(a);return;}for(;c<='9';++c){for(f=0;f<9;++f)if(a[i-i%27+i%9
    /3*3+f/3*9+f%3]==c||a[i%9+f*9]==c||a[i-i%9+f]==c)goto e;a[i]=c;J(a);a[i]
    ='0';e:;}}int main(int c,char**v){int t=0;if(c>1){for(;v[1][
    t];++t);if(t==81){J(v[1]);return 0;}}puts("sudoku [0-9]{81}");return 1;}

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