hdu 2608
2016-01-27 18:17
246 查看
0 or 1
Time Limit: 6000/2000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)[align=left]Problem Description[/align]
Solving problem is a interesting thing. Yifenfei like to slove different problem,because he think it is a way let him more intelligent. But as we know,yifenfei is weak in math. When he come up against a difficult math problem, he
always try to get a hand. Now the problem is coming! Let we
define T(n) as the sum of all numbers which are positive integers can divied n. and S(n) = T(1) + T(2) + T(3)…..+T(n).
[align=left]Input[/align]
The first line of the input contains an integer T which means the number of test cases. Then T lines follow, each line consists of only one positive integers n. You may assume the integer will not exceed 2^31.
[align=left]Output[/align]
For each test case, you should output one lines of one integer S(n) %2. So you may see the answer is always 0 or 1 .
[align=left]Sample Input[/align]
3
1
2
3
[align=left]Sample Output[/align]
1
0
0
HintHint S(3) = T(1) + T(2) +T(3) = 1 + (1+2) + (1+3) = 8
S(3) % 2 = 0
解题思路:这道题目我压根没思路,看了别人的解题报告。AC:
/* 分析:假设数n=2^k*p1^s1*p2^s2*p3^s3*...*pi^si;//k,s1...si>=0,p1..pi为n的素因子 所以T =(2^0+2^1+...+2^k)*(p1^0+p1^1+...+p1^s1)*...*(pi^0+pi^1+...+pi^si); 显然(2^0+2^1+...+2^k)%2=1,所以T 是0或1就取决于(p1^0+p1^1+...+p1^s1)*...*(pi^0+pi^1+...+pi^si) 而p1...pi都是奇数(除2之外的素数一定是奇数),所以(pi^0+pi^1+...+pi^si)只要有一个si为奇数(i=1...i) 则(pi^0+pi^1+...+pi^si)%2=0,则T %2=0//若si为奇数,则pi^si+1为偶数,pi^1+pi^2+...+pi^(si-1)为偶数(偶数个奇数和为偶数) 所以要T %2=1,则所有的si为偶数,则n=2^(k%2)*m^2;//m=2^(k/2)*p1^(s1/2)*p2^(s2/2)*...*pi^(si/2) 所以只要n为某个数的平方或者某个数的平方和则T %2=1,只要统计n的个数即可 */ #include<iostream> #include<cstdio> #include<cstdlib> #include<cstring> #include<string> #include<queue> #include<algorithm> #include<map> #include<cmath> #include<iomanip> #define INF 99999999 using namespace std; const int MAX=10; int main(){ int t,n; cin>>t; while(t--){ cin>>n; int sum=(int)sqrt(n*1.0)+(int)sqrt(n*1.0/2); cout<<sum%2<<endl; } return 0; }