OJ-Problems-Source/HDOJ/1041_autoAC.cpp
2016-08-12 10:14:21 +08:00

30 lines
796 B
C++

#include<iostream>
#include<string>
using namespace std;
string add(string s1,string s2){
if(s1.length()<s2.length()){
string temp=s1;
s1=s2;
s2=temp;
}
for(int i=s1.length()-1,j=s2.length ()-1;i>=0;i--,j--){
s1[i]=char(s1[i]+( j>=0 ? s2[j]-'0' : 0));
if(s1[i]-'0'>=10) {
s1[i]=char( (s1[i]-'0')%10+'0' );
if(i) s1[i-1]++;
else s1="1"+s1;
}
}
return s1;
}
string f[1005];
int main(){
int n;
f[1]="0"; f[2]="1"; f[3]="1"; f[4]="3"; f[5]="5"; f[6]="11";
for(int i=7;i<=1004;i++)
f[i]=add( f[i-1], add(f[i-2],f[i-2]) );
while(scanf("%d",&n)==1)
cout<<f[n]<<endl;
return 0;
}