-
Notifications
You must be signed in to change notification settings - Fork 2
/
l_dgraph.h
124 lines (106 loc) · 2.43 KB
/
l_dgraph.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
#ifndef _L_DGRAPH_H
#define _L_DGRAPH_H
#include "l.h"
class DirectedGraph{
public:
vector<vector<int> > adj;
int V;
int E;
vector<bool> marked;
vector<int> edgeTo;
vector<int> cycle;
vector<bool> onStack;
DirectedGraph(const char* filename) {
FILE* fp = fopen(filename, "r");
assert(fp);
fscanf(fp, "%d", &V);
fscanf(fp, "%d", &E);
int v, w;
for (int i = 0; i < V; ++i) {
adj.push_back(vector<int>());
}
for (int i = 0; i < E; i++) {
fscanf(fp, "%d %d", &v, &w);
adj[v].push_back(w);
}
marked = vector<bool>(V);
onStack = vector<bool>(V);
edgeTo = vector<int>(V);
for (int i = 0; i < V; i++) marked[i] = false;
for (int i = 0; i < V; i++) onStack[i] = false;
}
vector<int> dfs(int s) {
for (int i = 0; i < V; i++) marked[i] = false;
for (int i = 0; i < V; i++) onStack[i] = false;
vector<int> result;
dfs(s, result);
return result;
}
vector<int> bfs(int s) {
for (int i = 0; i < V; i++) marked[i] = false;
vector<int> result;
queue<int> Q;
marked[s] = true;
Q.push(s);
while (!Q.empty()) {
auto v = Q.front();
Q.pop();
result.push_back(v);
for (auto w : adj[v]) {
if (!marked[w]) {
marked[w] = true;
Q.push(w);
}
}
}
return result;
}
bool hasCycle() {
return !cycle.empty();
}
vector<int> topo_sort() {
vector<int> result;
for (auto i : marked) i = false;
for (int s = 0; s < V; ++s) {
if (!marked[s]) post_order_dfs(s, result);
}
reverse(result.begin(), result.end());
return result;
}
private:
void dfs(int v, vector<int> &result) {
onStack[v] = true;
marked[v] = true;
result.push_back(v);
for (auto w : adj[v]) {
if (hasCycle()) return;
else if (!marked[w]) {
edgeTo[w] = v;
dfs(w, result);
}
else if (onStack[w]) {
for (int x = v; x != w; x = edgeTo[x]) cycle.push_back(x);
cycle.push_back(w);
cycle.push_back(v);
reverse(cycle.begin(), cycle.end());
}
}
onStack[v] = false;
}
void post_order_dfs(int v, vector<int> &result) {
marked[v] = true;
for (auto w : adj[v])
if (!marked[w]) post_order_dfs(w, result);
result.push_back(v);
}
};
void p_dgraph(DirectedGraph* g) {
cout << "graph: " << endl;
int i = 0;
for (auto v : g->adj) {
cout << i++ << ": ";
for (auto i : v) cout << i << " ";
cout << endl;
}
}
#endif // !_L_DGRPAH_H