Hdu 2041 (Recursive, dp/combinatorial mathematics "is actually Fibonacci number")

The most classic Fibonacci number, the staircase can be one step at a time or two, ask how many middle-cross law;

For the last step or two, go to the level I, the total number of species is to go to the total number of I-1 + go to the total number of i-2; so a [i] = a [i-1] + a [i-2]; Of course, at that time I was using ' ' ' Combinatorial math '

1#include <stdio.h>2 Long LongCintAintb)3 {4     Long Longi,sum=1, J;5      for(i=a,j=1; i>=a-b+1, J<=b;i--, j + +) sum=sum*i/J;6     returnsum;7 }8 intMain ()9 {Ten     intN; One      while(SCANF ("%d", &n)! =EOF) A     { -         inti; -          for(i=0; i<n;i++)  the         { -             Long Longm,j,sum=0; -scanf"%i64d",&M); -             if(m!=1){ +m--; -              for(j=0; j<=m/2; j + +) Sum+=c (j+m-j*2, j); +             } Aprintf"%i64d\n", sum); at         } -     } -     return 0; -}

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Hdu 2041 (Recursive, dp/combinatorial mathematics "is actually Fibonacci number")