1009B Minimum Ternary String

B. Minimum Ternary String
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

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 holds aj=bjaj=bj, and ai<biai.

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
Copy
100210
output
Copy
001120
input
Copy
11222121
output
Copy
11112222
input
Copy
20
output
Copy
20


题意:给你一串字符只有0,1,2三种字符,如果1,2,或者0,1相邻,可以交换位置,只有0,2不能交换位置。输出经过这种方法,字典序最少的字符串。

题解:贪心  因为只有0和2位置不能交换,所以对于1来说没有影响,先把所有1的个数记录下来。然后从前往后遍历,遇见0就输出0,遇见1就跳过,遇见2把全部1输出,再输出2,然后后面的遇见0就输出0,遇见2输出2,遇见1跳过。

c++:

#include
using namespace std;
int num,flag;
int main()
{
    string s,a;
    cin>>s;
    for(int i=0; i

python:

s=input()
ans=''.join(c for c in s if c!='1')
i=(ans+'2').find('2')
print(ans[:i]+s.count('1')*'1'+ans[i:])

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