-
Notifications
You must be signed in to change notification settings - Fork 22
Expand file tree
/
Copy path205.interval-minimum-number.cpp
More file actions
113 lines (101 loc) · 3.16 KB
/
205.interval-minimum-number.cpp
File metadata and controls
113 lines (101 loc) · 3.16 KB
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
// Tag: Segment Tree
// Time: O(NlogN)
// Space: O(N)
// Ref: -
// Note: -
// Given an integer array (index from 0 to n-1, where n is the size of this array), and an query list.
// Each query has two integers `[start, end]`.
// For each query, calculate the minimum number between index start and end in the given array,and return in the result list.
//
// **Example 1:**
// ```
// Input : array: [1,2,7,8,5], queries :[(1,2),(0,4),(2,4)] .Output: [2,1,5]
// ```
// **Example 2:**
// ```
// Input : array: [4,5,7,1], queries :[(1,2),(1,3)]. Output: [5,1]
// ```
//
// We suggest you finish problem [Segment Tree Build](https://www.lintcode.com/problem/segment-tree-build/ ), [Segment Tree Query](https://www.lintcode.com/problem/segment-tree-query/) and [Segment Tree Modify](https://www.lintcode.com/problem/segment-tree-modify/) first.
/**
* Definition of Interval:
* class Interval {
* public:
* int start, end;
* Interval(int start, int end) {
* this->start = start;
* this->end = end;
* }
* }
*/
class SegmentTreeNode {
// platform has a hidden SegmentTreeNode, you can change SegmentTreeNode to MySegmentTreeNode to avoid confliction
public:
int start, end, min;
SegmentTreeNode *left, *right;
~SegmentTreeNode(){
delete left;
delete right;
}
SegmentTreeNode(int start, int end, int min): start(start), end(end), min(min), left(nullptr), right(nullptr) {}
};
class SegmentTree {
public:
SegmentTreeNode *root;
~SegmentTree(){
delete root;
}
SegmentTree(vector<int> &a) {
root = build(a, 0, a.size() - 1);
}
SegmentTreeNode *build(vector<int> &a, int start, int end) {
if (start > end) {
return nullptr;
}
SegmentTreeNode *node = new SegmentTreeNode(start, end, a[start]);
if (start == end) {
return node;
}
int mid = (start + end) / 2;
node->left = build(a, start, mid);
node->right = build(a, mid + 1, end);
node->min = min(node->left->min, node->right->min);
return node;
}
int query(SegmentTreeNode *node, int start, int end) {
if (!node) {
return INT_MAX;
}
if (start == node->start && end == node->end) {
return node->min;
}
int mid = (node->start + node->end) / 2;
if (end <= mid) {
return query(node->left, start, end);
} else if (start > mid) {
return query(node->right, start, end);
} else {
int left_val = query(node->left, start, mid);
int right_val = query(node->right, mid + 1, end);
return min(left_val, right_val);
}
}
};
class Solution {
public:
/**
* @param a: An integer array
* @param queries: An query list
* @return: The result list
*/
vector<int> intervalMinNumber(vector<int> &a, vector<Interval> &queries) {
// write your code here
SegmentTree t(a);
vector<int> res;
for (auto &q: queries) {
int val = t.query(t.root, q.start, q.end);
res.push_back(val);
}
return res;
}
};