PAT A1124 . Raffle for Weibo Followers (20)

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…

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#include <stdio.h>
#include <iostream>
#include <algorithm>
#include <string.h>
#include <string>
#include <queue>
#include <set>
#include <map>
using namespace std;
int m, n, s;
string temp;
vector<string> str;
map<string, int> mp;
int main(){
//freopen("in.txt", "r", stdin);

scanf("%d%d%d", &m, &n, &s);
str.resize(m);
if(s>m){ printf("Keep going...\n"); return 0;}
for (int i = 0; i < m; i++){
cin>>str[i];
}
int t = s - 1;
while(t < m){
if(mp[str[t]] != 1){
mp[str[t]] = 1;
cout<<str[t]<<endl;
t+= n;
}else{
t++;
}
}
return 0;

}