CodeForces 830B

将每个数字的位置存进该数字的vector中

原数组排个序从小到大处理，每次在vector里二分找到距离当前位置“最远”的位置（相差最大），更新答案

树状数组维护每个数字现在的位置和原位置之差

#include <bits/stdc++.h>
using namespace std;
#define LL long long
const int N = 100005;
int n;
int a[N], b[N];
vector<int> v[N];
int c[N];
void modify(int x, int num)
{
    while (x <= 100000) c[x] += num, x += x&-x;
}
int sum(int x)
{
    int s = 0;
    while (x) s += c[x], x -= x&-x;
    return s;
}
int main()
{
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) scanf("%d", &a[i]), b[i] = a[i];
    sort(b+1, b+1+n);
    for (int i = 1; i <= n; i++)
        v[a[i]].push_back(i);
    LL ans = 0;
    int now = 0;
    for (int i = 1; i <= n;)
    {
        int p = lower_bound(v[b[i]].begin(), v[b[i]].end(), now) - v[b[i]].begin();
        if (p == 0)
        {
            int pos = v[b[i]][v[b[i]].size()-1];
            ans += pos - sum(pos) - (now - sum(now));
            now = pos;
        }
        else
        {
            int pos = v[b[i]][p-1];
            ans += n - sum(n) - (now-sum(now)) + pos - sum(pos);
            now = pos;
        }
        for (int j = 0; j < v[b[i]].size(); j++) modify(v[b[i]][j], 1);
        i += v[b[i]].size();
    }
    cout << ans << endl;
}