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authorYuqian Yang <crupest@crupest.life>2025-02-28 23:13:39 +0800
committerYuqian Yang <crupest@crupest.life>2025-02-28 23:13:39 +0800
commitdc1f0c4c0096013799416664894c5194dc7e1f52 (patch)
tree2f5d235f778cd720f4c39ec3e56b77ba6d99f375 /works/solutions/acwing/1215.cpp
parent7299d424d90b1effb6db69e3476ddd5af72eeba4 (diff)
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chore(store): move everything to store.
Diffstat (limited to 'works/solutions/acwing/1215.cpp')
-rw-r--r--works/solutions/acwing/1215.cpp59
1 files changed, 0 insertions, 59 deletions
diff --git a/works/solutions/acwing/1215.cpp b/works/solutions/acwing/1215.cpp
deleted file mode 100644
index d6832b3..0000000
--- a/works/solutions/acwing/1215.cpp
+++ /dev/null
@@ -1,59 +0,0 @@
-#include <cstring>
-#include <iostream>
-
-const int MAX = 1000010; // Why 1000001 is not ok!?
-
-int n;
-int H[100001];
-int bit[MAX];
-int reverse_pairs[100001];
-
-int lowbit(int x) { return x & -x; }
-
-void add(int x, int y) {
- for (int i = x; i < MAX; i += lowbit(i)) {
- bit[i] += y;
- }
-}
-
-int query(int x) {
- int result = 0;
- for (int i = x; i != 0; i -= lowbit(i)) {
- result += bit[i];
- }
- return result;
-}
-
-int main() {
- std::ios_base::sync_with_stdio(false);
- std::cin.tie(nullptr);
-
- std::cin >> n;
-
- for (int i = 1; i <= n; i++) {
- std::cin >> H[i];
- H[i]++;
- }
-
- for (int i = 1; i <= n; i++) {
- add(H[i], 1);
- reverse_pairs[i] = i - query(H[i]);
- }
-
- std::memset(bit, 0, sizeof bit);
-
- for (int i = n; i >= 1; i--) {
- add(H[i], 1);
- reverse_pairs[i] += query(H[i] - 1);
- }
-
- long long result = 0;
-
- for (int i = 1; i <= n; i++) {
- result += (1LL + reverse_pairs[i]) * reverse_pairs[i] / 2;
- }
-
- std::cout << result;
-
- return 0;
-}