Atcode ABC105-C：Base -2 Number

C - Base -2 Number

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Time Limit: 2 sec / Memory Limit: 1024 MB

Score : 300300 points

Problem Statement

Given an integer NN, find the base −2−2 representation of NN.

Here, SS is the base −2−2 representation of NN when the following are all satisfied:

• SS is a string consisting of 0 and 1.
• Unless S=S= 0, the initial character of SS is 1.
• Let S=SkSk−1...S0S=SkSk−1...S0, then S0×(−2)0+S1×(−2)1+...+Sk×(−2)k=NS0×(−2)0+S1×(−2)1+...+Sk×(−2)k=N.

It can be proved that, for any integer MM, the base −2−2 representation of MM is uniquely determined.

Constraints

• Every value in input is integer.
• −109≤N≤109−109≤N≤109

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Input

Input is given from Standard Input in the following format:N

Output

Print the base −2 representation of N.

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Sample Input 1 Copy

Copy

-9

Sample Output 1 Copy

Copy

1011

As (−2)0+(−2)1+(−2)3=1+(−2)+(−8)=−9(−2)0+(−2)1+(−2)3=1+(−2)+(−8)=−9, 1011 is the base −2 representation of −9.

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Sample Input 2 Copy

Copy

123456789

Sample Output 2 Copy

Copy

11000101011001101110100010101

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Sample Input 3 Copy

Copy

0

Sample Output 3 Copy

Copy

0

题意

输入一个数，求该数的负二进制数

先记下来，代码不是太理解，明天慢慢看

#include <bits/stdc++.h>
using namespace std;
const int maxn=1e6+10;
int a[maxn];
int main(int argc, char const *argv[])
{
	int n;
	cin>>n;
	if(n==1||n==0)
	{
		cout<<n<<endl;
		return 0;
	}
	int k=0;
	while(n)
	{
		int m=n;
		a[k++]=abs(n)%2;
		n/=-2;
		if(m<0&&abs(m)%2)
			n++;
	}
	for(int i=k-1;i>=0;i--)
		cout<<a[i];
	cout<<endl;
	return 0;
}