PAT 甲级 1124. 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…

#include <iostream>#include <map>using namespace std;int main(){    int n,m,s;    cin>>n>>m>>s;    map<string,int> mapp;    bool flag=false;    for(int i=1;i<=n;i++){        string str;        cin>>str;        if(mapp[str]==1)            s+=1;        if(mapp[str]==0&&i==s)        {            cout<<str<<endl;            flag=true;            mapp[str]=1;            s+=m;        }    }    if(!flag)        cout<<"Keep going..."<<endl;    return 0;}