CodeForces - 1009B Minimum Ternary String

You are given a ternary string (it is a string which consists only of characters '0', '1' and '2').

You can swap any two adjacent (consecutive) characters '0' and '1' (i.e. replace "01" with "10" or vice versa) or any two adjacent (consecutive) characters '1' and '2' (i.e. replace "12" with "21" or vice versa).

For example, for string "010210" we can perform the following moves:

  • "010210" → "100210";
  • "010210" → "001210";
  • "010210" → "010120";
  • "010210" → "010201".

Note than you cannot swap "02" → "20" and vice versa. You cannot perform any other operations with the given string excluding described above.

You task is to obtain the minimum possible (lexicographically) string by using these swaps arbitrary number of times (possibly, zero).

String aa is lexicographically less than string bb (if strings aa and bb have the same length) if there exists some position ii (1i|a|1≤i≤|a|, where |s||s| is the length of the string ss) such that for every j<ij<i holds aj=bjaj=bj, and ai<biai<bi.

Input

The first line of the input contains the string ss consisting only of characters '0', '1' and '2', its length is between 11 and 105105 (inclusive).

Output

Print a single string — the minimum possible (lexicographically) string you can obtain by using the swaps described above arbitrary number of times (possibly, zero).

Examples

Input
100210
Output
001120
Input
11222121
Output
11112222
Input
20
Output
20



开始时想的过于狭隘了,局部分析未果的情况下,没有做到整体的去分析。

对 0 1 2 的特点进行分析,1 既可以与 0 交换 ,也可以与 2 交换 ,所以说 1 可以出现在字符串的任意位置,为了使字符串的字典序小,1 必定要出现在 2 的前面,且要出现在第一个 2 的前面,所以 1 的位置就确定了。
再看 0 2 ,因为所有的 1 已经都被抽到了第一个 2 的前面,且 2 不能借助 1 使它本身换到 0 的后面(以 2 1 0为例),所以,第一个 2 后面的序列是不变的。
再看第一个 2 前面的序列,显然,第一个 2 之前的 0 要在所有的 1 之前。
分析完毕。

切入点:0 1 2 的特点、字符串的格式

 1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<cstring>
 4 #include<string>
 5 #include<cmath>
 6 #include<algorithm>
 7 #include<queue>
 8 #include<stack>
 9 #include<deque>
10 #include<map>
11 #include<iostream>
12 using namespace std;
13 typedef long long  LL;
14 const double pi=acos(-1.0);
15 const double e=exp(1);
16 const int N = 100009;
17 
18 char con[100009];
19 int main()
20 {
21     int i,p,j,n,k;
22     int head,tail,a=0,b=0,flag;
23 
24     scanf("%s",con);
25     k=strlen(con);
26     for(i=0;i<k;i++)
27     {
28         if(con[i]=='1')
29             a++;
30     }
31     flag=0;
32     for(i=0;i<k;i++)
33     {
34         if(con[i]=='0')
35             printf("0");
36         else if(con[i]=='2'&&flag==0)
37         {
38             for(j=1;j<=a;j++)
39                 printf("1");
40             printf("2");
41             flag=1;
42         }
43         else if(con[i]=='2'&&flag==1)
44         {
45             printf("2");
46         }
47     }
48     if(flag==0)
49     {
50         for(i=1;i<=a;i++)
51             printf("1");
52     }
53     return 0;
54 }
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posted @ 2018-10-04 11:25  Daybreaking  阅读(262)  评论(0编辑  收藏  举报