3141221_ce.cpp

部分PKU上的源码

#include<iostream.h>
int w(int a,int b,int c);
int main()
{int a,b,c;
while(!(a==-1&&b==-1&&c==-1))
{cin>>a>>b>>c;
cout<<w(a,b,c);}
return 1;
}
int w(int a,int b,int c)
{int k=1;
if(a>20||b>20||c>20) return w(20,20,20);
if(a<=0||b<=0||c<=0) return 1;
if(a==b&&b==c) 
{switch(a)
{case 1:return 2;
 case 2:return 4; 
	case 3:return 8; 
		case 4:return 16; 
			case 5:return 32; 
				case 6:return 64; 
					case 7:return 128; 
						case 8:return 256; 
							case 9:return 512; 
								case 10:return 1024; 
									case 11:return 2048; 
										case 12:return 4096; 
											case 13:return 8192; 
												case 14:return 16384; 
													case 15:return 32768; 
														case 16:return 65536; 
															case 17:return 131072; 
																case 18:return 262114; 
																	case 19:return 524288; 
																	case 20:return 1048576; }

 if (a<b&&b<c) return (w(a,b,c-1)+w(a,b-1,c-1)-w(a,b-1,c) );
 else return (w(a-1,b,c)+w(a-1,b-1,c)+w(a-1,b,c-1)-w(a-1,b-1,c-1));
}