USACO Section 3.1: Contact

算法简单，写起来遇到些小问题

 /*
 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++) {
         ; 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);
     ;
     ;
     ;
     while (step <= N && cur < res.size()) {
         //cout << endl << "step: " << step << endl;
          || res[cur].frequency != res[cur-].frequency) {
             pre = cur;
             if (step == N) break;
             if (cur) fout << endl;
             fout << res[cur].frequency << endl;
             fout << res[cur].content;
             step++;
         }
         else {
              == ) fout << endl << res[cur].content;
             else fout << " " << res[cur].content;
         }
         cur++;
     }
     fout << endl;

     ;
 }