B. Queue at the School
time limit per test 2
seconds
memory limit per test 256
megabytes
input standard input
output standard output
During the break the
schoolchildren, boys and girls, formed a queue of n people in
the canteen. Initially the children stood in the order they entered the
canteen. However, after a while the boys started feeling awkward for standing
in front of the girls in the queue and they started letting the girls move
forward each second.
Let's describe the process more precisely.
Let's say that the positions in the queue are sequentially numbered by integers
from 1 to n, at that the person in the position
number 1 is served first. Then, if at time x a boy
stands on the i-th position and a girl stands on the (i + 1)-th
position, then at time x + 1 the i-th position
will have a girl and the (i + 1)-th position will have a boy. The
time is given in seconds.
You've got the initial position of the
children, at the initial moment of time. Determine the way the queue is going
to look after t seconds.
Input
The first line contains two integers n and t (1 ≤ n, t ≤ 50),
which represent the number of children in the queue and the time after which
the queue will transform into the arrangement you need to find.
The next line contains string s,
which represents the schoolchildren's initial arrangement. If the i-th
position in the queue contains a boy, then the i-th character of
string s equals "B", otherwise the i-th
character equals "G".
Output
Print string a,
which describes the arrangement after t seconds. If the i-th
position has a boy after the needed time, then the i-th
character a must equal "B", otherwise it must equal
"G".
Examples
input
5 1
BGGBG
output
GBGGB
input
5 2
BGGBG
output
GGBGB
input
4 1
GGGB
output
GGGB
Solution
- [tab]
- C++
#include<iostream> #include<string> using namespace std; int main() { int n,t; string s; cin>>n>>t>>s; while(t--) { for(int i=1;i<n;i++) { if(s[i]=='G' && s[i-1]=='B') { s[i]='B'; s[i-1]='G'; i++; } } } cout<<s<<endl; return 0; }