Submission #845984
Source Code Expand
//操作2は「2つ飛ばしの要素を交換」と読み直せる -> indexの偶奇が大事!。 //奇数indexにあってソート後に偶数indexになるもの, 偶数indexにあってソート後に奇数indexになるものの個数を数える。 //それを2で割ったものが下界。 #include <iostream> #include <algorithm> using namespace std; int n; int a[100000]; int b[100000]; int main() { int i; cin >> n; for (i = 0; i < n; i++) cin >> a[i]; for (i = 0; i < n; i++) b[i] = a[i]; sort(b, b + n); int ans = 0; for (i = 0; i < n; i++) { int index = lower_bound(b, b + n, a[i]) - b; if (index % 2 != i % 2) { ans++; } } ans /= 2; cout << ans << endl; return 0; }
Submission Info
Submission Time | |
---|---|
Task | C - BBuBBBlesort! |
User | startcpp |
Language | C++14 (GCC 5.4.1) |
Score | 600 |
Code Size | 740 Byte |
Status | AC |
Exec Time | 127 ms |
Memory | 1024 KB |
Judge Result
Set Name | Sample | All | ||||
---|---|---|---|---|---|---|
Score / Max Score | 0 / 0 | 600 / 600 | ||||
Status |
|
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Set Name | Test Cases |
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Sample | s1.txt, s2.txt |
All | 01.txt, 02.txt, 03.txt, 04.txt, 05.txt, 06.txt, 07.txt, 08.txt, 09.txt, 10.txt, 11.txt, 12.txt, 13.txt, 14.txt, 15.txt, 16.txt, 17.txt, 18.txt, 19.txt, 20.txt, 21.txt, 22.txt, s1.txt, s2.txt |
Case Name | Status | Exec Time | Memory |
---|---|---|---|
01.txt | AC | 113 ms | 1024 KB |
02.txt | AC | 111 ms | 1024 KB |
03.txt | AC | 113 ms | 1024 KB |
04.txt | AC | 127 ms | 1024 KB |
05.txt | AC | 92 ms | 1024 KB |
06.txt | AC | 91 ms | 1024 KB |
07.txt | AC | 90 ms | 1024 KB |
08.txt | AC | 107 ms | 1024 KB |
09.txt | AC | 76 ms | 1024 KB |
10.txt | AC | 73 ms | 1024 KB |
11.txt | AC | 76 ms | 1024 KB |
12.txt | AC | 73 ms | 1024 KB |
13.txt | AC | 74 ms | 1024 KB |
14.txt | AC | 91 ms | 1024 KB |
15.txt | AC | 91 ms | 1024 KB |
16.txt | AC | 91 ms | 1024 KB |
17.txt | AC | 94 ms | 1024 KB |
18.txt | AC | 4 ms | 256 KB |
19.txt | AC | 4 ms | 256 KB |
20.txt | AC | 4 ms | 256 KB |
21.txt | AC | 4 ms | 256 KB |
22.txt | AC | 4 ms | 256 KB |
s1.txt | AC | 4 ms | 256 KB |
s2.txt | AC | 4 ms | 256 KB |