Use variable parameters to print the tree output of recursive functions

For the call steps to trace recursive functions, you can use the variable parameter ##__ va_args _ to define the macro for output. The following uses the solution of Fibonacci as an example:

1 # include <cstdio> 2 3 # define log (Level, FMT ,...) do {If (true) 4 {for (INT I = 0; I <level-1; I ++) printf ("--"); 5 printf (FMT "\ n", ##__ va_args _) ;}} while (false) 6 7 unsigned Fibonacci (unsigned N, int level) 8 {9 log (level, "Maid (% d)", n); 10 if (n <2) 11 return N; 12 else 13 return maid (n-1, LEVEL + 1) + maid (n-2, level + 1); 14} 15 16 int main () 17 {18 maid (6, 1); 19 Return 0; 20}

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Use variable parameters to print the tree output of recursive functions