John got a full mark on PAT. He was so happy that he decided to hold a raffle（抽奖） for his followers on Weibo -- that is, he would select winners from every N followers who forwarded his post, and give away gifts. Now you are supposed to help him generate the list of winners.
Input Specification:
Each input file contains one test case. For each case, the first line gives three positive integers M (≤ 1000), N and S, being the total number of forwards, the skip number of winners, and the index of the first winner (the indices start from 1). Then M lines follow, each gives the nickname (a nonempty string of no more than 20 characters, with no white space or return) of a follower who has forwarded John's post.
Note: it is possible that someone would forward more than once, but no one can win more than once. Hence if the current candidate of a winner has won before, we must skip him/her and consider the next one.
Output Specification:
For each case, print the list of winners in the same order as in the input, each nickname occupies a line. If there is no winner yet, print Keep going... instead.
Sample Input 1:
9 3 2
Imgonnawin!
PickMe
PickMeMeMeee
LookHere
Imgonnawin!
TryAgainAgain
TryAgainAgain
Imgonnawin!
TryAgainAgain
Sample Output 1:
PickMe
Imgonnawin!
TryAgainAgain
Sample Input 2:
2 3 5
Imgonnawin!
PickMe
Sample Output 2:
Keep going...
#include<iostream>
#include<algorithm>
#include<vector>
#include<unordered_set>
using namespace std;
int main(){
int m, n , s;
cin >> m >> n >> s;
vector<string> vec(m + 1);
unordered_set<string> un_set;
for(int i = 1; i <= m; i++){
cin >> vec[i];
}
int index = s;
if(s > m){
cout << "Keep going..." << endl;
}else
{
while (index <= m)
{
if(un_set.find(vec[index]) == un_set.end()){
un_set.insert(vec[index]);
cout << vec[index] << endl;
}else
{
while (un_set.find(vec[index]) != un_set.end())
{
index++;
// cout << index << "====" << endl;
}
if(index <= m){
un_set.insert(vec[index]);
cout << vec[index] << endl;
}
}
index = index + n;
}
}
return 0;
}