/*
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2,fma,bmi,bmi2,sse4.2,popcnt,lzcnt")
*/
#include <bits/stdc++.h>
#define taskname ""
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define i64 long long
#define pb push_back
#define ff first
#define ss second
#define isz(x) (int)x.size()
using namespace std;
const int mxN = 2e5 + 5;
const int mod = 1e9 + 7;
const i64 oo = 1e18;
struct FenwickTree {
int n;
vector<int> data;
FenwickTree(int n) : n(n), data(n + 1) {}
void update(int idx, int val) {
for (; idx <= n; idx += idx & -idx)
data[idx] += val;
}
int get(int idx) {
int res = 0;
for (; idx > 0; idx -= idx & -idx)
res += data[idx];
return res;
}
};
i64 res;
int n, a[mxN];
vector<pair<int, int>> v;
void solve() {
cin >> n;
for (int i = 1; i <= n; ++i) {
cin >> a[i];
v.emplace_back(a[i], i);
}
sort(all(v));
FenwickTree fenw(n);
for (int i = 0; i < n;) {
int ptr = i;
while (ptr < n && v[ptr].ff == v[i].ff) {
int lt = fenw.get(v[ptr].ss), rt = i - lt;
res += 1ll * lt * rt;
++ptr;
}
for (int j = i; j < ptr; ++j)
fenw.update(v[j].ss, 1);
i = ptr;
}
cout << res << endl;
}
signed main() {
#ifndef CDuongg
if(fopen(taskname".inp", "r"))
assert(freopen(taskname".inp", "r", stdin)), assert(freopen(taskname".out", "w", stdout));
#else
freopen("bai3.inp", "r", stdin);
freopen("bai3.out", "w", stdout);
auto start = chrono::high_resolution_clock::now();
#endif
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int t = 1; //cin >> t;
while(t--) solve();
#ifdef CDuongg
auto end = chrono::high_resolution_clock::now();
cout << "\n"; for(int i = 1; i <= 100; ++i) cout << '=';
cout << "\nExecution time: " << chrono::duration_cast<chrono::milliseconds> (end - start).count() << "[ms]" << endl;
cout << "Check array size pls sir" << endl;
#endif
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
600 KB |
Output is correct |
2 |
Runtime error |
5 ms |
4048 KB |
Execution killed with signal 11 |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
21 ms |
3540 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
21 ms |
3540 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
344 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
344 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
21 ms |
3540 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
600 KB |
Output is correct |
2 |
Runtime error |
5 ms |
4048 KB |
Execution killed with signal 11 |
3 |
Halted |
0 ms |
0 KB |
- |