CSES - Aalto Competitive Programming 2024 - wk4 - Homework - Results
Submission details
Task:Dynamic Range Minimum Queries
Sender:fabiank
Submission time:2024-09-23 13:06:46 +0300
Language:C++ (C++20)
Status:READY
Result:ACCEPTED
Test results
testverdicttime
#1ACCEPTED0.00 sdetails
#2ACCEPTED0.46 sdetails

Compiler report

input/code.cpp: In function 'std::vector<int> create_segment_tree(std::vector<int>&, int)':
input/code.cpp:53:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |     for (int i = 0; i < values.size(); i++)
      |                     ~~^~~~~~~~~~~~~~~

Code

#include <bits/stdc++.h>
using namespace std;
vector<int> create_segment_tree(vector<int> &values, int n);
void update_segment_tree(vector<int> &seg_tree, int i, int u, int n);
int query_segment_tree(vector<int> &seg_tree, int a, int b, int n);
int next_power_2(int x);
void print_vector(vector<int> &x);
// approach: SegmentTrees
int main()
{
int n, q;
cin >> n >> q;
vector<int> values(n);
for (int i = 0; i < n; i++)
{
cin >> values[i];
}
int seg_tree_n = next_power_2(n);
vector<int> seg_tree = create_segment_tree(values, seg_tree_n);
for (int i = 0; i < q; i++)
{
int type;
cin >> type;
if (type == 1)
{
int k, u;
cin >> k >> u;
k--;
update_segment_tree(seg_tree, k, u, seg_tree_n);
}
else
{
int a, b;
cin >> a >> b;
a--;
b--;
int query_result = query_segment_tree(seg_tree, a, b, seg_tree_n);
cout << query_result << "\n";
}
}
}
vector<int> create_segment_tree(vector<int> &values, int n)
{
vector<int> seg_tree(2 * n, INT32_MAX);
for (int i = 0; i < values.size(); i++)
{
seg_tree[n + i] = values[i];
}
for (int i = n - 1; i > 0; i--)
{
seg_tree[i] = min(seg_tree[2 * i], seg_tree[2 * i + 1]);
}
return seg_tree;
}
void update_segment_tree(vector<int> &seg_tree, int i, int u, int n)
{
// print_vector(seg_tree);
int k = i + n;
// cout << "i: " << i << " - u: " << u << " - n: " << n << " - k: " << k << endl;
seg_tree[k] = u;
for (k /= 2; k >= 1; k /= 2)
{
// cout << "k: " << k << endl;
// print_vector(seg_tree);
seg_tree[k] = min(seg_tree[2 * k], seg_tree[2 * k + 1]);
}
}
int query_segment_tree(vector<int> &seg_tree, int a, int b, int n)
{
a += n;
b += n;
int result = INT32_MAX;
while (a <= b)
{
if (a % 2 == 1)
{
result = min(result, seg_tree[a++]);
}
if (b % 2 == 0)
{
result = min(result, seg_tree[b--]);
}
a /= 2;
b /= 2;
}
return result;
}
int next_power_2(int x)
{
// int exponent = ceil(log2(x));
// return pow(2, exponent);
int power_2 = 1;
while (power_2 <= x)
{
power_2 = power_2 << 1;
}
return power_2;
}
void print_vector(vector<int> &x)
{
for (int v : x)
{
cout << v << " ";
}
cout << "\n";
}

Test details

Test 1

Verdict: ACCEPTED

input
8 80
7 6 4 6 2 9 4 8
2 1 1
2 1 2
2 1 3
...

correct output
7
6
4
4
2
...

user output
7
6
4
4
2
...
Truncated

Test 2

Verdict: ACCEPTED

input
200000 200000
398739055 65343131 699208332 3...

correct output
28609
129890
20378
20378
311522
...

user output
28609
129890
20378
20378
311522
...
Truncated