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
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
|
#include <iostream>
#include <climits>
#include <vector>
#include <queue>
struct node
{
int data;
node* left = nullptr;
node* right = nullptr;
node(int data_, node* left_ = nullptr, node* right_ = nullptr) :
data(data_),
left(left_),
right(right_) {}
};
// Task 01: Check if tree is bst
bool is_bst_rec(node* root, int left_interval, int right_interval)
{
if(root == nullptr)
return true;
if(root->data < left_interval || root->data > right_interval)
return false;
return is_bst_rec(root->left, left_interval, root->data) &&
is_bst_rec(root->right, root->data, right_interval);
}
bool is_bst(node* root)
{
return is_bst_rec(root, INT_MIN, INT_MAX);
}
// Task 02: check if root to leaf paths form a progression
// Solved in two ways.
bool is_progression(const std::vector<int>& v)
{
if(v.size() <= 2)
return true;
int offset = v[1] - v[0];
for (size_t i = 1; i < v.size() - 1; i++)
{
if(v[i+1] - v[i] != offset)
return false;
}
return true;
}
void progression_rec(node* root, std::vector<int>& current_path)
{
if(root == nullptr)
{
return;
}
current_path.push_back(root->data);
if(!root->left && !root->right)
{
if(is_progression(current_path))
{
for(int x : current_path)
{
std::cout << x << " ";
}
std::cout << std::endl;
}
}
progression_rec(root->right, current_path);
progression_rec(root->left, current_path);
current_path.pop_back();
}
void get_progression_dummy(node* root)
{
std::vector<int> path;
progression_rec(root, path);
}
void get_progression_offset(node* root, int offset, std::vector<int>& current_path)
{
if(root == nullptr)
return;
current_path.push_back(root->data);
if(!root->left && !root->right)
{
for(int x : current_path)
{
std::cout << x << " ";
}
std::cout << std::endl;
}
if(root->left)
{
int left_offset = root->left->data - root->data;
if(left_offset == offset)
{
get_progression_offset(root->left, offset, current_path);
}
}
if(root->right)
{
int eight_offset = root->right->data - root->data;
if(eight_offset == offset)
{
get_progression_offset(root->right, offset, current_path);
}
}
current_path.pop_back();
}
void get_progression(node* root)
{
if(root == nullptr)
return;
std::vector<int> path;
path.push_back(root->data);
if(root->left)
{
int offset = root->left->data - root->data;
get_progression_offset(root->left, offset, path);
}
if(root->right)
{
int offset = root->right->data - root->data;
get_progression_offset(root->right, offset, path);
}
}
// Task 03: check if any level forms a progression
// solved in two ways
unsigned height(node* root)
{
if(root == nullptr)
return 0;
return 1 + std::max(height(root->left), height(root->right));
}
void fill_levels(node* root, std::vector<std::vector<int>>& levels, unsigned current_level)
{
if(root == nullptr)
return;
levels[current_level].push_back(root->data);
fill_levels(root->left, levels, current_level + 1);
fill_levels(root->right, levels, current_level + 1);
}
void get_progression_dummy_levels(node* root)
{
if(root == nullptr)
return;
std::vector<std::vector<int>> levels;
levels.resize(height(root));
fill_levels(root, levels, 0);
for(const std::vector<int>& level : levels)
{
if(is_progression(level))
{
for(int x : level)
{
std::cout << x << ' ';
}
std::cout << std::endl;
}
}
}
void get_progression_levels(node* root)
{
if(root == nullptr)
return;
std::queue<node*> q;
q.push(root);
while(q.size())
{
std::vector<int> current_level;
current_level.resize(q.size());
unsigned idx = 0;
size_t elements_in_level = q.size();
for (size_t i = 0; i < elements_in_level; i++)
{
node* current_node = q.front();
q.pop();
current_level[idx++] = current_node->data;
if(current_node->left)
q.push(current_node->left);
if(current_node->right)
q.push(current_node->right);
}
if(is_progression(current_level))
{
for(int x : current_level)
{
std::cout << x << " ";
}
std::cout << std::endl;
}
}
}
int main()
{
}
|
