foo.cc: In function 'int main()':
foo.cc:20:19: error: cannot convert 'const char*' to 'FILE* {aka _IO_FILE*}' for argument '1' to 'int fprintf(FILE*, const char*, ...)'
     fprintf("%d",n);
                   ^
foo.cc: In function 'int hanoi(int)':
foo.cc:12:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

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