递归函数（Recursion of function）

hduacm2044

   
     

    
      
    
      #include
    
      "
    
      iostream
    
      "
    
      
#include 
    
      <
    
      cstdio
    
      >
    
      

    
      using
    
       
    
      namespace
    
       std;
__int64 m[
    
      51
    
      ];

    
      int
    
       main()
{
 
    
      int
    
       n,i,a,b;
 
 m[
    
      1
    
      ]
    
      =
    
      1
    
      ;m[
    
      2
    
      ]
    
      =
    
      1
    
      ;
 
    
      for
    
      (i
    
      =
    
      3
    
      ;i
    
      <=
    
      50
    
      ;i
    
      ++
    
      )
 {
 m[i]
    
      =
    
      m[i
    
      -
    
      2
    
      ]
    
      +
    
      m[i
    
      -
    
      1
    
      ];
 
 }
 
 scanf(
    
      "
    
      %d
    
      "
    
      ,
    
      &
    
      n);
 
    
      while
    
      (n
    
      --
    
      )
 {
 scanf(
    
      "
    
      %d %d
    
      "
    
      ,
    
      &
    
      a,
    
      &
    
      b);
 
    
      if
    
      (a
    
      >
    
      0
    
      &&
    
      a
    
      <
    
      b
    
      &&
    
      b
    
      <
    
      50
    
      )
 printf(
    
      "
    
      %I64d\n
    
      "
    
      ,m[b
    
      -
    
      a
    
      +
    
      1
    
      ]);
 

 }
 
    
      return
    
       
    
      0
    
      ;
} 
   
     

 

hduacm2045

   
     

    
      
    
       1 
    
      #include
    
      "
    
      iostream
    
      "
    
      

    
       2 
    
       
    
      using
    
       
    
      namespace
    
       std;

    
       3 
    
       
    
      int
    
       main()

    
       4 
    
      { 

    
       5 
    
       
    
      int
    
       n,i;

    
       6 
    
       __int64 a[
    
      51
    
      ]
    
      =
    
      {
    
      0
    
      ,
    
      3
    
      ,
    
      6
    
      ,
    
      6
    
      };

    
       7 
    
       
    
      while
    
      (scanf(
    
      "
    
      %d
    
      "
    
      ,
    
      &
    
      n)
    
      !=
    
      EOF)

    
       8 
    
       {

    
       9 
    
       

    
      10 
    
       
    
      if
    
      (n
    
      >=
    
      4
    
      &&
    
      n
    
      <=
    
      50
    
      )

    
      11 
    
       {

    
      12 
    
       
    
      for
    
      (i
    
      =
    
      4
    
      ;i
    
      <=
    
      n;i
    
      ++
    
      )

    
      13 
    
       a[i]
    
      =
    
      a[i
    
      -
    
      1
    
      ]
    
      +
    
      2
    
      *
    
      a[i
    
      -
    
      2
    
      ];

    
      14 
    
       }

    
      15 
    
       printf(
    
      "
    
      %I64d\n
    
      "
    
      ,a[n]);

    
      16 
    
       }

    
      17 
    
       
    
      return
    
       
    
      0
    
      ;

    
      18 
    
      }
   
     

 

hduacm2046

   
     

    
      
    
       1 
    
      #include
    
      "
    
      iostream
    
      "
    
      

    
       2 
    
       
    
      using
    
       
    
      namespace
    
       std;

    
       3 
    
       
    
      int
    
       main()

    
       4 
    
      {

    
       5 
    
       __int64 a[
    
      55
    
      ]
    
      =
    
      {
    
      0
    
      ,
    
      1
    
      ,
    
      2
    
      };

    
       6 
    
       
    
      int
    
       n,i;

    
       7 
    
      

    
       8 
    
       
    
      for
    
      (i
    
      =
    
      3
    
      ;i
    
      <
    
      55
    
      ;i
    
      ++
    
      )

    
       9 
    
       a[i]
    
      =
    
      a[i
    
      -
    
      1
    
      ]
    
      +
    
      a[i
    
      -
    
      2
    
      ];

    
      10 
    
       
    
      while
    
      (cin
    
      >>
    
      n
    
      &&
    
      n
    
      !=
    
      0
    
      )

    
      11 
    
       {

    
      12 
    
       
    
      if
    
      (n
    
      >
    
      0
    
      &&
    
      n
    
      <=
    
      50
    
      )

    
      13 
    
       printf(
    
      "
    
      %I64d\n
    
      "
    
      ,a[n]);

    
      14 
    
       }

    
      15 
    
       
    
      return
    
       
    
      0
    
      ;

    
      16 
    
      }

    
      17 
    
       
   
     

 

hduacm2050

   
     

    
      
    
       1 
    
      #include
    
      "
    
      iostream
    
      "
    
      

    
       2 
    
      using
    
       
    
      namespace
    
       std;

    
       3 
    
      int
    
       main()

    
       4 
    
      {

    
       5 
    
       
    
      int
    
       i, c,a[
    
      1000
    
      ],sum;

    
       6 
    
       
    
      while
    
      (cin
    
      >>
    
      c)

    
       7 
    
       { 

    
       8 
    
       
    
      for
    
      (i
    
      =
    
      0
    
      ;i
    
      <
    
      c;i
    
      ++
    
      )

    
       9 
    
       cin
    
      >>
    
      a[i];

    
      10 
    
       
    
      for
    
      (i
    
      =
    
      0
    
      ;i
    
      <
    
      c;i
    
      ++
    
      )

    
      11 
    
       
    
      if
    
      (a[i]
    
      >
    
      0
    
      &&
    
      a[i]
    
      <=
    
      10000
    
      )

    
      12 
    
       {

    
      13 
    
       sum
    
      =
    
      2
    
      *
    
      a[i]
    
      *
    
      a[i]
    
      -
    
      a[i]
    
      +
    
      1
    
      ;

    
      14 
    
       cout
    
      <<
    
      sum
    
      <<
    
      endl;

    
      15 
    
       }

    
      16 
    
       }

    
      17 
    
       
    
      return
    
       
    
      0
    
      ;

    
      18 
    
      }