USACO Section 3.1: Contact

/*
ID: yingzho1
LANG: C++
TASK: contact
*/
#include <iostream>
#include <fstream>
#include <string>
#include <map>
#include <vector>
#include <set>
#include <algorithm>
#include <stdio.h>
#include <queue>
#include <cstring>
#include <cmath>
#include <list>

using namespace std;

ifstream fin("contact.in");
ofstream fout("contact.out");

int A, B, N;
string input;

struct fre {
int frequency;
string content;
};

//bool cmp(const int &a, const int &b) {return a > b;}
bool cmp(const fre &a, const fre &b) {
if (a.frequency == b.frequency) {
if (a.content.size() == b.content.size()) return a.content < b.content;
else return a.content.size() < b.content.size();
}
else return a.frequency > b.frequency;
}

int main()
{
fin >> A >> B >> N;
while (!fin.eof()) {
string frag;
getline(fin, frag);
if (!input.size()) input = frag;
else input = input + frag;
}
map<string, int> rec;
for (int len = A; len <= B; len++) {
for (int cur = 0; cur + len <= input.size(); cur++) {
rec[input.substr(cur, len)]++;
}
}
vector<fre> res;
for (map<string, int>::iterator it = rec.begin(); it != rec.end(); it++) {
fre tmp;
tmp.frequency = it->second;
tmp.content = it->first;
res.push_back(tmp);
}
sort(res.begin(), res.end(), cmp);
int step = 0;
int cur = 0;
int pre = 0;
while (step <= N && cur < res.size()) {
//cout << endl << "step: " << step << endl;
if (cur == 0 || res[cur].frequency != res[cur-1].frequency) {
pre = cur;
if (step == N) break;
if (cur) fout << endl;
fout << res[cur].frequency << endl;
fout << res[cur].content;
step++;
}
else {
if ((cur-pre) % 6 == 0) fout << endl << res[cur].content;
else fout << " " << res[cur].content;
}
cur++;
}
fout << endl;

return 0;
}