題目：
There are n employees in Alternative Cake Manufacturing (ACM). They are now voting on some very important question and the leading world media are trying to predict the outcome of the vote.
Each of the employees belongs to one of two fractions: depublicans or remocrats, and these two fractions have opposite opinions on what should be the outcome of the vote. The voting procedure is rather complicated:
- Each of n employees makes a statement. They make statements one by one starting from employees 1and finishing with employee n. If at the moment when it's time for the i-th employee to make a statement he no longer has the right to vote, he just skips his turn (and no longer takes part in this voting).
- When employee makes a statement, he can do nothing or declare that one of the other employees no longer has a right to vote. It's allowed to deny from voting people who already made the statement or people who are only waiting to do so. If someone is denied from voting he no longer participates in the voting till the very end.
- When all employees are done with their statements, the procedure repeats: again, each employees starting from 1 and finishing with n who are still eligible to vote make their statements.
- The process repeats until there is only one employee eligible to vote remaining and he determines the outcome of the whole voting. Of course, he votes for the decision suitable for his fraction.
You know the order employees are going to vote and that they behave optimal (and they also know the order and who belongs to which fraction). Predict the outcome of the vote.
The first line of the input contains a single integer n (1 ≤ n ≤ 200 000) — the number of employees.
The next line contains n characters. The i-th character is 'D' if the i-th employee is from depublicans fraction or 'R' if he is from remocrats.
Print 'D' if the outcome of the vote will be suitable for depublicans and 'R' if remocrats will win.
5 DDRRR
D
6 DDRRRR
R
Consider one of the voting scenarios for the first sample:
- Employee 1 denies employee 5 to vote.
- Employee 2 denies employee 3 to vote.
- Employee 3 has no right to vote and skips his turn (he was denied by employee 2).
- Employee 4 denies employee 2 to vote.
- Employee 5 has no right to vote and skips his turn (he was denied by employee 1).
- Employee 1 denies employee 4.
- Only employee 1 now has the right to vote so the voting ends with the victory of depublicans.
這個題目打virtual contest 時沒有讀懂題，然後去看了看題解報告，知道真相的我眼淚掉下來，就是每個人按順序，可以踢一個人或者啥都不做，問最後剩那個幫派。立下flag，以後再也不用Google翻譯整篇文章了，自己慢慢讀題吧，順便提高一下閱讀能力。TAT
貪心策略，每次踢離他最近的敵方的人，爲什麼，因爲這樣的話，例如DRDR，可以減少自己方的一個人的傷亡，同時踢掉敵方的一個人。貪心嘛，就是要腦洞大，膽大心細。用隊列來實現，相對順序用序號來實現。
code：
#include<cstdio>
#include<queue>
using namespace std;
queue<int>D,R;
int main(){
int n;scanf("%d",&n);getchar();
for(int i=0;i<n;++i){
char ch=getchar();
if(ch=='D')D.push(i);
else R.push(i);
}
//當某一隊被踢乾淨就勝利了
while(!D.empty()&&!R.empty()){
int a=D.front(),b=R.front();
D.pop();R.pop();
if(a<b)D.push(a+n);//a在b的前面，a把b踢了，a進入下一輪，用a+n表示
else R.push(b+n);//同理
}
if(D.empty())putchar('R');
else putchar('D');
}