学步园

POJ 2591 Set Definition

算是简单题了,

双迭代

 #include <iostream><br /> #include <algorithm><br /> using namespace std;<br /> long s[10000005];<br /> int main()<br /> {<br /> int i,j,k,m,n,t;<br /> s[0] = 1;<br /> j = 0;<br /> k=1;<br /> i=0;<br /> for (;k<=10000000;)<br /> {<br /> if (s[i]*2+1 < s[j]*3+1)<br /> {<br /> s[k] = s[i]*2+1;<br /> k++;<br /> i++;<br /> }<br /> else if (s[i]*2+1 > s[j]*3+1)<br /> {<br /> s[k] = s[j]*3+1;<br /> k++;<br /> j++;<br /> }<br /> else<br /> i++;<br /> }<br /> while (scanf("%d",&n)!=EOF)<br /> {<br /> printf("%d/n",s[n-1]);<br /> }<br /> return 0;<br /> }