// compile: make data // run: ./data < data.in #include <bits/stdc++.h> using namespace std; #pragma GCC optimize("O3,unroll-loops") #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt") #ifdef LOCAL #include <debug/codeforces.h> #define debug(x...) _debug_print(#x, x); #define Debug(x...) _debug_print_format(#x, x); std::ifstream terminal("/dev/tty"); #define PP cerr<<"\033[1;30mpause...\e[0m",terminal.ignore(); #else #define debug(x...) #define Debug(x...) #define PP #endif template<typename...Args> void print_(Args...args){((cout<<args<<" "),...)<<endl;} #define rep(i,a,b) for(int i=(a);i<(int)(b);++i) #define sz(v) ((int)(v).size()) #define print(...) print_(__VA_ARGS__); #define FIND(a, x) ((find(a.begin(),a.end(),(x))!=a.end())?1:0) #define cmin(x,...) x=min({(x),__VA_ARGS__}) #define cmax(x,...) x=max({(x),__VA_ARGS__}) #define INTMAX (int)(9223372036854775807) #define INF (int)(1152921504606846976) #define NaN (int)(0x8b88e1d0595d51d1) #define double long double #define int long long #define uint unsigned long long #define MAXN 200010 template <class T> struct segtree { struct node { int l, r; T val; node *ch[2]; }; int cnt = 0; T DEFAULT_VALUE; node *newnode(int l, int r) { node *x = &datalist[cnt++]; x->l = l, x->r = r; x->ch[0] = x->ch[1] = nullptr; x->val.L = l, x->val.R = r; return x; } vector<int> a; vector<node> datalist; node *root; segtree(vector<int> arr) { a = arr, build(); } void pushup(node *x) { if (!x) return; if (!x->ch[0] && !x->ch[1]) return; if (x->ch[0]) pushdown(x->ch[0]); if (x->ch[1]) pushdown(x->ch[1]); if (x->ch[0] && x->ch[1]) x->val = x->ch[0]->val + x->ch[1]->val; else x->val = x->ch[!x->ch[0]]->val; } void pushdown(node *x) { if (!x) return; if (x->ch[0]) x->val.pushdown(x->ch[0]->val, 0); if (x->ch[1]) x->val.pushdown(x->ch[1]->val, 1); x->val.clear(); } T query(int ql, int qr) { function<T(node*)> dfs = [&](node *x) -> T { if (ql > x->r || qr < x->l) return DEFAULT_VALUE; pushdown(x); if (x->l >= ql && x->r <= qr) return x->val; return dfs(x->ch[0]) + dfs(x->ch[1]); }; return dfs(root); } template <typename U> void modify(int ql, int qr, U val) { function<void(node*)> dfs = [&](node *x) -> void { if (ql > x->r || qr < x->l) return; pushdown(x); if (x->l >= ql && x->r <= qr) { x->val.update(val, ql, qr); return; } dfs(x->ch[0]), dfs(x->ch[1]); pushup(x); }; dfs(root); } void build() { datalist.resize(sz(a) * 2); function<node*(int, int)> dfs = [&](int l, int r) { node *x = newnode(l, r); if (r > l) x->ch[0] = dfs(l, (l+r) >> 1), x->ch[1] = dfs(((l+r)>>1) + 1, r); else x->val.set(l, a[l]); pushup(x); return x; }; root = dfs(0, sz(a)-1); } void graphviz_dump(string filename = "graph.dot") { FILE *f = fopen(filename.c_str(), "w"); fprintf(f, "digraph {\n"); rep(i, 0, cnt) { node *x = &datalist[i]; fprintf(f, " %lld;\n"); } rep(i, 0, cnt) { node *x = &datalist[i]; if (x->ch[0]) fprintf(f, " %lld -> %ld;\n", i, x->ch[0] - &datalist[0]); if (x->ch[1]) fprintf(f, " %lld -> %ld;\n", i, x->ch[1] - &datalist[0]); } fprintf(f, "}\n"); } }; int32_t main() { ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); struct value { int minv = INF, minpos = 0, tag = 0, offset = 0; int L, R; value operator+(const value &other) const { value res; if (minv < other.minv) res.minv = minv, res.minpos = minpos, res.offset = offset; else res.minv = other.minv, res.minpos = other.minpos, res.offset = other.offset; return res; } void set(int pos, int val) { this->minv = val; this->minpos = pos; this->offset = 0; } void update(pair<int, int> val, int ql = 0, int qr = 0) { // first: rk, second: val if (val.first == NaN) { assert(ql == qr); this->minv = val.second; } else this->tag += val.first; } void pushdown(value &child, int rc) { child.update({this->tag, NaN}, child.L, child.R); } void clear() { this->offset += this->tag; this->tag = 0; } }; int n; cin >> n; vector<int> a(n); rep(i, 0, n) cin >> a[i]; segtree<value> t(a); // t.graphviz_dump(); int ans = 0; for (int len = n-1; len >= 0; --len) { auto it = t.query(0, n-1); int pos = it.minpos + it.offset; ans += min(pos, len-pos); t.modify(it.minpos, it.minpos, make_pair(NaN, INF)); t.modify(it.minpos+1, n-1, make_pair(-1, NaN)); } cout << ans << endl; return 0; }
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