Light, more light
Time Limit: 3000ms
Memory Limit: 131072KB
This problem will be judged on UVA.
Original ID: 10110
64-bit integer IO format: %lld
Java class name: Main
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Type:
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Stable Marriage Problem
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Flow
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DFS-like
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Nim Sprague-Grundy Number
Matrix Gaussian Elimination
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Sorting
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Aho Corasick Knuth-Morris-Pratt
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Basic Math Big Integer Arithmetic
Number Theory Chinese Remainder Theorem
Extended Euclid
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Bitmask Beginner
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Tag it!
| Light, more light |
The Problem
There is man named "mabu" for switching on-off light in our University. He switches on-off the lights in a corridor. Every bulb has its own toggle switch. That is, if it is pressed then the bulb turns on. Another press will turn it off. To save power consumption
(or may be he is mad or something else) he does a peculiar thing. If in a corridor there is `n‘ bulbs, he walks along the corridor back and forth `n‘ times and in i‘th walk he toggles only the switches whose serial is divisable by i. He does not press any
switch when coming back to his initial position. A i‘th walk is defined as going down the corridor (while doing the peculiar thing) and coming back again.
Now you have to determine what is the final condition of the last bulb. Is it on or off?
The Input
The input will be an integer indicating the n‘th bulb in a corridor. Which is less then or equals 2^32-1. A zero indicates the end of input. You should not process this input.
The Output
Output "yes" if the light is on otherwise "no" , in a single line.
Sample Input
3 6241 8191 0
Sample Output
no yes no
AC代码：
#include <iostream>
#include <cmath>
using namespace std;
int main()
{
int n;
while(cin>>n,n)
{
int x=sqrt(n*1.0);
if(x*x==n)
cout<<"yes"<<endl;
else
cout<<"no"<<endl;
}
return 0;
}