1 #include <iostream>
2 #include <list>
3 #include <vector>
4
5  using namespace std;
6
7  // If 2 recruiting meetings are conflicting
8  bool IsConflict(const vector<bool>& v1, const vector<bool>& v2)
9 {
10 for(int i = 0; i < v1.size(); ++i)
11 {
12 if(v1[i] && v2[i]) return true;
13 }
14 return false;
15 }
16
17  // merge 2 recruiting meetings: v2 will be held at the same time of v1
18  void Merge(vector<bool>& v1, const vector<bool>& v2)
19 {
20 for(int i = 0; i < v1.size(); ++i)
21 {
22 v1[i] = v1[i] || v2[i];
23 }
24 }
25
26  // input: input[m][n], 2d array to represents students' selection of meetings. row stands for meetings, column stands for students,
27 // and array value stands for if a student select a meeting
28 // next: The meeting to check
29 // curTime: Time required so far
30 // curArrangement: record the information of which meeting is merged with another meeting
31 // best[output]:The best time
32 // bestArrangement[output] : The best arragement
33 void ArrangeRecruitings(vector<vector<bool> >& input, int next, int& curTime, vector<list<int> >& curArrangement, int& bestTime, vector<list<int> >& bestArrangement)
34 {
35 int m = input.size();
36 // base cases
37 if(next >= m)
38 {
39 // Save the best one
40 if(curTime < bestTime)
41 {
42 bestTime = curTime;
43 bestArrangement = curArrangement;
44 }
45
46 return;
47 }
48 else
49 {
50 // recursive cases
51 for(int i = 0; i <= next; ++i)
52 {
53
54 if(curArrangement[i].empty()) continue; // if already merged with other ones, just skip it
55
56 if (!IsConflict(input[i], input[next]))
57 {
58
59 // update the status
60 vector<bool> bkI = input[i];
61 Merge(input[i], input[next]);
62
63 curArrangement[next].pop_back();
64 curArrangement[i].push_back(next);
65
66 // Consider next one after merge
67 ArrangeRecruitings(input, next+1, curTime, curArrangement, bestTime, bestArrangement);
68
69 // restore the status
70 curArrangement[i].pop_back();
71 curArrangement[next].push_back(next);
72
73 input[i] = bkI;
74 }
75 }
76
77 // Consider next one without any merge
78 ArrangeRecruitings(input, next+1, ++curTime, curArrangement, bestTime, bestArrangement);
79
80 }
81 }
82
83
84 int main()
85 {
86 // 1. Initializing
87 int m = 3;
88 int n = 4;
89
90 vector<vector<bool> > input(m, vector<bool>(n, false));
91
92 input[0][0] = true;
93 input[0][1] = true;
94
95 input[1][1] = true;
96 input[1][2] = true;
97
98 input[2][2] = true;
99 input[2][3] = true;
100
101 //input[0][2] = true;
102
103 int curTime = 1;
104 int bestTime = m+1;
105 vector<list<int> > curArrangement(m);
106 vector<list<int> > bestArrangement(m);
107 for(int i = 0; i < m; ++i) curArrangement[i].push_back(i);
108
109 // 2. Solve
110 ArrangeRecruitings(input, 1, curTime, curArrangement, bestTime, bestArrangement);
111
112 // 3. Output the result
113 cout << "Totoal Time: " << bestTime << endl;
114 for(int i = 0; i < m; ++i)
115 {
116 cout << i << "): ";
117 if(bestArrangement[i].empty())
118 {
119 cout << "none" << endl;
120 continue;
121 }
122 for(list<int>::const_iterator it = bestArrangement[i].begin(); it != bestArrangement[i].end(); ++it)
123 cout << *it << "-";
124
125 cout << endl;
126 }
127 }