Skew Binary
| Time Limit: 1000MS | Memory Limit: 10000K | |
| Total Submissions: 10676 | Accepted: 6807 |
Description
When a number is expressed in decimal, the kth digit represents a multiple of 10k. (Digits are numbered from right to left, where the least significant digit is number 0.) For example,
81307(10) = 8 * 10^4 + 1 * 10 ^3 + 3 * 10^2 + 0 * 10^1 + 7 * 10^0
= 80000 + 1000 + 300 + 0 + 7
= 81307.
When a number is expressed in binary, the kth digit represents a multiple of 2^k . For example,
10011(2) = 1 * 2^4 + 0 * 2^3 + 0 * 2^2 + 1 * 2^1 + 1 * 2^0
= 16 + 0 + 0 + 2 + 1
= 19.
In skew binary, the kth digit represents a multiple of 2^(k+1)-1. The only possible digits are 0 and 1, except that the least-significant nonzero digit can be a 2. For example,
10120(skew) = 1 * (2^5-1) + 0 * (2^4-1) + 1 * (2^3-1) + 2 * (2^2-1) + 0 * (2^1-1)
= 31 + 0 + 7 + 6 + 0
= 44.
The first 10 numbers in skew binary are 0, 1, 2, 10, 11, 12, 20, 100, 101, and 102. (Skew binary is useful in some applications because it is possible to add 1 with at most one carry. However, this has nothing to do with the current problem.)
81307(10) = 8 * 10^4 + 1 * 10 ^3 + 3 * 10^2 + 0 * 10^1 + 7 * 10^0
= 80000 + 1000 + 300 + 0 + 7
= 81307.
When a number is expressed in binary, the kth digit represents a multiple of 2^k . For example,
10011(2) = 1 * 2^4 + 0 * 2^3 + 0 * 2^2 + 1 * 2^1 + 1 * 2^0
= 16 + 0 + 0 + 2 + 1
= 19.
In skew binary, the kth digit represents a multiple of 2^(k+1)-1. The only possible digits are 0 and 1, except that the least-significant nonzero digit can be a 2. For example,
10120(skew) = 1 * (2^5-1) + 0 * (2^4-1) + 1 * (2^3-1) + 2 * (2^2-1) + 0 * (2^1-1)
= 31 + 0 + 7 + 6 + 0
= 44.
The first 10 numbers in skew binary are 0, 1, 2, 10, 11, 12, 20, 100, 101, and 102. (Skew binary is useful in some applications because it is possible to add 1 with at most one carry. However, this has nothing to do with the current problem.)
Input
The input contains one or more lines, each of which contains an integer n. If n = 0 it signals the end of the input, and otherwise n is a nonnegative integer in skew binary.
Output
For each number, output the decimal equivalent. The decimal value of n will be at most 2^31-1 = 2147483647.
Sample Input
10120 200000000000000000000000000000 10 1000000000000000000000000000000 11 100 11111000001110000101101102000 0
Sample Output
44 2147483646 3 2147483647 4 7 1041110737
大水题。
代码：
#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <algorithm>
#include <cmath>
using namespace std;
string test;
int main()
{
while(cin>>test)
{
if(test=="0")
break;
int len = test.length();
int i,k=1,result=0;
for(i=len-1;i>=0;i--)
{
result = result+ (int)(test[i]-'0')*(int)(pow((double)2,k)-1);
k++;
}
cout<<result<<endl;
}
return 0;
}
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