HDU 5752Sqrt Bo

Sqrt Bo

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)
Total Submission(s): 145    Accepted Submission(s): 72


Problem Description
Let's define the function f(n)=n−−√.

Bo wanted to know the minimum number y which satisfies fy(n)=1.

note:f1(n)=f(n),fy(n)=f(fy1(n))

It is a pity that Bo can only use 1 unit of time to calculate this function each time.

And Bo is impatient, he cannot stand waiting for longer than 5 units of time.

So Bo wants to know if he can solve this problem in 5 units of time.
 
Input
This problem has multi test cases(no more than 120).

Each test case contains a non-negative integer n(n<10100).
 
Output
For each test case print a integer - the answer y or a string "TAT" - Bo can't solve this problem.
 
Sample Input
233 233333333333333333333333333333333333333333333333333333333
 
Sample Output
3
TAT
 
直接java暴力
import java.math.*;
import java.util.*;
public class Main{

    /**
     * @param args
     */
    public static void main(String[] args) {
        Scanner cin=new Scanner(System.in);
        BigDecimal n;
        BigDecimal tmp=new BigDecimal("10");
        BigDecimal tmpp=new BigDecimal("0");
        MathContext mc = new MathContext(1000,RoundingMode.HALF_DOWN);
        int ans;
        while(cin.hasNext()){
            ans=-1;
            n=cin.nextBigDecimal();
            if(n.compareTo(tmpp)==0){
                System.out.println("TAT");continue;
            }
            for(int j=1;j<=5;j++){
                BigDecimal d = new BigDecimal(Math.sqrt(n.doubleValue()),mc);
                n=d;
                if(n.compareTo(tmp)<0){
                    if(n.intValue()==1){
                        ans=j;break;
                    }
                }
            }
            if(ans!=-1)System.out.println(ans);
            else System.out.println("TAT");
        }
    }

}
原文地址:https://www.cnblogs.com/pk28/p/5708633.html