1124. Raffle for Weibo Followers (20)

青旅半醒 2021-09-19 03:50 189阅读 0赞

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>
    #include <vector>
    #include <algorithm>
    using namespace std;
    
    int main(){
        int m, n, s;
        string st;
        cin >> m >> n >> s;
        vector<string> v;
        map <string, bool> ma;
        for (int i = 0; i < m; i++) {
            cin >> st;
            v.push_back(st);
        }
        for (int i = s-1; i < v.size(); i = i + n) {
            while(ma[v[i]]){
                i++;
            }
            cout << v[i] << endl;
            ma[v[i]] = true;
        }
        if(m < s) cout << "Keep going...\n";
        
        return 0;
    }