P3908 异或之和

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<cmath>
 5 #include<algorithm>
 6 #define lli long long int 
 7 using namespace std;
 8 const int MAXN=10000001;
 9 const int mod=1e9+7;
10 inline void read(int &n)
11 {
12     char c=getchar();n=0;bool flag=0;
13     while(c<'0'||c>'9')    c=='-'?flag=1,c=getchar():c=getchar();
14     while(c>='0'&&c<='9')    n=n*10+c-48,c=getchar();n=flag==1?-n:n;
15 }
16 
17 int main()
18 {
19     long long n=0;
20     cin>>n;
21         if(n%4==1)    printf("1");
22         else if(n%4==3)    printf("0");
23         else     if(n%4==2)printf("%lld",n+1);
24         else     if(n%4==0)    printf("%lld",n);
25     return 0;
26 }