hdu 2042 - 不容易系列之二

题意：（略）太长了

解法：找规律，发现A[i]=A[i-1]*2-2;

   1:  #include<stdlib.h>

   2:  #include<string.h>

   3:  #include<stdio.h>

   4:  #include<math.h>

   5:  #define N 31

   6:  int a[N]={3};

   7:  void init(){

   8:      int i;

   9:      for(i=1;i<N;i++){

  10:          a[i]=a[i-1]*2-2;//这个就是递推式

  11:      }

  12:  }

  13:  int main(){

  14:      int n,i;

  15:      init();

  16:      while(scanf("%d",&n)!=EOF){

  17:          while(n--){

  18:              int tmp;

  19:              scanf("%d",&tmp);

  20:              printf("%d\n",a[tmp]);

  21:          }

  22:      }

  23:  }

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }