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| # pragma optimize("O3")
# pragma GCC optimize ("Ofast")
# pragma GCC optimize ("unroll-loops")
# pragma GCC target("sse,sse2,sse3,ssse3,sse4,avx,avx2")
#include <iostream>
#include <list>
using namespace std;
int main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
list<char> l;
string data;
char cmd;
cin>>data;
int m, pos = data.length();
for(int i = 0; i < data.length(); ++i)
l.push_back(data[i]);
cin>>m;
list<char>::iterator it = l.end();
--it;
for(int i = 0; i < m; ++i){
cin>>cmd;
switch (cmd) {
case 'L':
if(pos) --pos, --it; break;
case 'D':
++it, ++pos;
if(it == l.end()) --pos, --it; break;
case 'B':
if(pos) l.erase(it--), --pos;
break;
case 'P': cin>>cmd; l.insert(++it, cmd); --it; ++pos; break;
}
}
for(char c : l)
cout<<c;
}
|
