wuxikai @ 2024-10-09 12:37:09
#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 5e5 + 7;
long long n, q;
long long c[N], a[N];
void update(int i, long long x)
{
for (; i <= n; i += i & -i)
c[i] += x;
}
long long query(int i)
{
long long ans = 0;
for (; i; i -= i & -i)
{
ans += c[i];
}
return ans;
}
signed main()
{
long long ans = 0;
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n;
for (int i = 1; i <= n; i++)
{
cin >> a[i];
}
for (int i = 1; i <= n; i++)
{
update(a[i], 1);
long long sum = query(a[i]);
ans += i - sum;
}
cout << ans;
return 0;
}
by wangborui123 @ 2024-10-09 12:56:29
这题需要离散化吧
by wuxikai @ 2024-10-09 16:30:24
40分WA 改了离散化之后只有40pts咋办啊━┳━ ━┳━
by wuxikai @ 2024-10-09 17:02:12
100分好了现在AC了谢谢指导