#include <bits/stdc++.h>
#include <cassert>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,fma")
#include <sys/stat.h>
#include <sys/mman.h>
#include <unistd.h>
using namespace std;
/////////////////////////////////////////////////////////////////////////////////////////////
/*
* Author : jinhan814
* Date : 2021-05-06
* Source : https://blog.naver.com/jinhan814/222266396476
* Description : FastIO implementation for cin, cout. (mmap ver.)
*/
constexpr int SZ = 1 << 20;
class INPUT {
private:
char* p;
bool __END_FLAG__, __GETLINE_FLAG__;
public:
explicit operator bool() { return !__END_FLAG__; }
INPUT() {
struct stat st; fstat(0, &st);
p = (char*)mmap(0, st.st_size, PROT_READ, MAP_SHARED, 0, 0);
}
bool IsBlank(char c) { return c == ' ' || c == '\n'; }
bool IsEnd(char c) { return c == '\0'; }
char _ReadChar() { return *p++; }
char ReadChar() {
char ret = _ReadChar();
for (; IsBlank(ret); ret = _ReadChar());
return ret;
}
template<typename T> T ReadInt() {
T ret = 0; char cur = _ReadChar(); bool flag = 0;
for (; IsBlank(cur); cur = _ReadChar());
if (cur == '-') flag = 1, cur = _ReadChar();
for (; !IsBlank(cur) && !IsEnd(cur); cur = _ReadChar()) ret = 10 * ret + (cur & 15);
if (IsEnd(cur)) __END_FLAG__ = 1;
return flag ? -ret : ret;
}
string ReadString() {
string ret; char cur = _ReadChar();
for (; IsBlank(cur); cur = _ReadChar());
for (; !IsBlank(cur) && !IsEnd(cur); cur = _ReadChar()) ret.push_back(cur);
if (IsEnd(cur)) __END_FLAG__ = 1;
return ret;
}
double ReadDouble() {
string ret = ReadString();
return stod(ret);
}
string getline() {
string ret; char cur = _ReadChar();
for (; cur != '\n' && !IsEnd(cur); cur = _ReadChar()) ret.push_back(cur);
if (__GETLINE_FLAG__) __END_FLAG__ = 1;
if (IsEnd(cur)) __GETLINE_FLAG__ = 1;
return ret;
}
friend INPUT& getline(INPUT& in, string& s) { s = in.getline(); return in; }
} _in;
class OUTPUT {
private:
char write_buf[SZ];
int write_idx;
public:
~OUTPUT() { Flush(); }
explicit operator bool() { return 1; }
void Flush() {
write(1, write_buf, write_idx);
write_idx = 0;
}
void WriteChar(char c) {
if (write_idx == SZ) Flush();
write_buf[write_idx++] = c;
}
template<typename T> int GetSize(T n) {
int ret = 1;
for (n = n >= 0 ? n : -n; n >= 10; n /= 10) ret++;
return ret;
}
template<typename T> void WriteInt(T n) {
int sz = GetSize(n);
if (write_idx + sz >= SZ) Flush();
if (n < 0) write_buf[write_idx++] = '-', n = -n;
for (int i = sz; i-- > 0; n /= 10) write_buf[write_idx + i] = n % 10 | 48;
write_idx += sz;
}
void WriteString(string s) { for (auto& c : s) WriteChar(c); }
void WriteDouble(double d) { WriteString(to_string(d)); }
} _out;
/* operators */
INPUT& operator>> (INPUT& in, char& i) { i = in.ReadChar(); return in; }
INPUT& operator>> (INPUT& in, string& i) { i = in.ReadString(); return in; }
template<typename T, typename std::enable_if_t<is_arithmetic_v<T>>* = nullptr>
INPUT& operator>> (INPUT& in, T& i) {
if constexpr (is_floating_point_v<T>) i = in.ReadDouble();
else if constexpr (is_integral_v<T>) i = in.ReadInt<T>(); return in;
}
OUTPUT& operator<< (OUTPUT& out, char i) { out.WriteChar(i); return out; }
OUTPUT& operator<< (OUTPUT& out, string i) { out.WriteString(i); return out; }
template<typename T, typename std::enable_if_t<is_arithmetic_v<T>>* = nullptr>
OUTPUT& operator<< (OUTPUT& out, T i) {
if constexpr (is_floating_point_v<T>) out.WriteDouble(i);
else if constexpr (is_integral_v<T>) out.WriteInt<T>(i); return out;
}
/* macros */
#define fastio 1
#define cin _in
#define cout _out
#define istream INPUT
#define ostream OUTPUT
/////////////////////////////////////////////////////////////////////////////////////////////
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
#define MAX 1010101
#define MAXS 500
#define INF 1000000020
#define bb ' '
#define ln '\n'
#define Ln '\n'
#define MOD 1000003
struct node {
int mn;
int mn2;
int cnt;
int mnl, mnr;
node(int x = 0, int ind = 0) {
mnl = mnr = ind;
if (!~x) {
mn = mn2 = cnt = -1;
return;
}
mn = x;
mn2 = INF;
cnt = 1;
}
};
inline node operator+(node n1, node n2) {
if (!~n1.cnt) return n2;
if (!~n2.cnt) return n1;
node ret;
ret.mn = min(n1.mn, n2.mn);
ret.cnt = 0;
ret.mnl = INF;
ret.mnr = -INF;
if (ret.mn == n1.mn) ret.cnt += n1.cnt, ret.mnl = min(ret.mnl, n1.mnl), ret.mnr = max(ret.mnr, n1.mnr);
else ret.mn2 = min(ret.mn2, n1.mn);
if (ret.mn == n2.mn) ret.cnt += n2.cnt, ret.mnl = min(ret.mnl, n2.mnl), ret.mnr = max(ret.mnr, n2.mnr);
else ret.mn2 = min(ret.mn2, n2.mn);
ret.mn2 = min(ret.mn2, n1.mn2);
ret.mn2 = min(ret.mn2, n2.mn2);
return ret;
}
int N;
int H[MAX];
int ch[MAX];
namespace segtree {
int N;
node tree[MAX * 4];
int lazy[MAX * 4];
void init(int s, int e, int loc = 1) {
lazy[loc] = -1;
if (s == e) {
tree[loc] = node(H[s], s);
return;
}
int m = s + e >> 1;
init(s, m, loc * 2);
init(m + 1, e, loc * 2 + 1);
tree[loc] = tree[loc * 2] + tree[loc * 2 + 1];
}
inline void prop(int loc) {
for (auto c : { loc * 2, loc * 2 + 1 }) {
tree[c].mn = max(tree[c].mn, lazy[loc]);
lazy[c] = max(lazy[c], lazy[loc]);
assert(tree[c].mn < tree[c].mn2);
}
lazy[loc] = -1;
}
inline void upd(int s, int e, int l, int r, int v, int loc = 1) {
if (s != e) prop(loc);
if (e < l || r < s) return;
if (l <= s && e <= r) {
if (v < tree[loc].mn2) {
if (v > tree[loc].mn) {
tree[loc].mn = v;
lazy[loc] = max(lazy[loc], v);
}
return;
}
}
int m = s + e >> 1;
upd(s, m, l, r, v, loc * 2);
upd(m + 1, e, l, r, v, loc * 2 + 1);
tree[loc] = tree[loc * 2] + tree[loc * 2 + 1];
}
void upd(int low, int r, int v) { upd(1, N, low, r, v); }
inline node query(int s, int e, int l, int r, int loc = 1) {
if (s != e) prop(loc);
if (e < l || r < s) return node(-1);
if (l <= s && e <= r) return tree[loc];
int m = s + e >> 1;
return query(s, m, l, r, loc * 2) + query(m + 1, e, l, r, loc * 2 + 1);
}
inline node query(int l, int r) { return query(1, N, l, r); }
}
inline ll rsum(ll n) { return (n * (n + 1) / 2) % MOD; }
inline ll rsum(ll l, ll r) { return rsum(r) - rsum(l - 1); }
namespace minseg {
int tree[MAX * 4];
void init(int s, int e, int loc = 1) {
if (s == e) {
tree[loc] = H[s];
return;
}
int m = s + e >> 1;
init(s, m, loc * 2);
init(m + 1, e, loc * 2 + 1);
tree[loc] = min(tree[loc * 2], tree[loc * 2 + 1]);
}
inline void prop(int loc) { for (auto c : { loc * 2, loc * 2 + 1 }) tree[c] = max(tree[c], tree[loc]); }
inline void upd(int s, int e, int l, int r, int x, int loc = 1) {
if (s != e) prop(loc);
if (e < l || r < s) return;
if (l <= s && e <= r) {
tree[loc] = max(tree[loc], x);
return;
}
int m = s + e >> 1;
upd(s, m, l, r, x, loc * 2);
upd(m + 1, e, l, r, x, loc * 2 + 1);
tree[loc] = min(tree[loc * 2], tree[loc * 2 + 1]);
}
inline void upd(int l, int r, int x) { upd(1, N, l, r, x); }
inline int get(int s, int e, int i, int loc = 1) {
if (s != e) prop(loc);
if (e < i || i < s) return INF;
if (s == e) return tree[loc];
int m = s + e >> 1;
return min(get(s, m, i, loc * 2), get(m + 1, e, i, loc * 2 + 1));
}
inline int get(int i) { return get(1, N, i); }
}
signed main() {
ios::sync_with_stdio(false), cin.tie(0);
cin >> N;
segtree::N = N;
int i;
ll ans = 0;
int mv = 1;
for (i = 1; i <= N; i++) cin >> H[i];
for (i = 1; i <= N; i++) if (H[mv] < H[i]) mv = i;
for (i = 1; i <= N; i++) ch[i] = H[i];
for (i = 1; i <= mv; i++) ch[i] = max(ch[i], ch[i - 1]);
for (i = N; i >= mv; i--) ch[i] = max(ch[i], ch[i + 1]);
for (i = 1; i <= N; i++) ans += rsum(H[i], ch[i] - 1), ans %= MOD;
segtree::init(1, N);
minseg::init(1, N);
int low, high;
low = high = -1;
for (i = 1; i < N; i++) if (H[i] > H[i + 1]) {
low = i;
break;
}
if (!~low) {
cout << 0 << ln;
return 0;
}
for (i = N; i > 1; i--) if (H[i] > H[i - 1]) {
high = i;
break;
}
if (!~high) {
cout << 0 << ln;
return 0;
}
if (low >= high) {
cout << 0 << ln;
return 0;
}
set<int> lst, rst;
for (i = 1; i <= low; i++) lst.insert(H[i]);
for (i = high; i <= N; i++) rst.insert(H[i]);
int rot = 0;
while (low < high) {
rot++;
assert(rot <= N * 10);
while (low < N && minseg::get(low) <= minseg::get(low + 1)) low++, lst.insert(H[low]);
while (high > 1 && minseg::get(high) <= minseg::get(high - 1)) high--, rst.insert(H[high]);
if (low >= high) break;
auto res = segtree::query(low + 1, high - 1);
int mn = res.mn;
int n = res.cnt;
auto itl = lst.upper_bound(mn);
auto itr = rst.upper_bound(mn);
int up = min(res.mn2, min(*itl, *itr));
int ml = min(*itl, segtree::query(low, res.mnl).mn2);
int mr = min(*itr, segtree::query(res.mnr, high).mn2);
if (res.cnt == 1) {
ans += 1ll * (ml + mr) * (up - mn);
segtree::upd(low, high, up);
minseg::upd(low, high, up);
ans %= MOD;
continue;
}
ans += rsum(mn + 1, up) * (n * 2 - 3);
ans %= MOD;
ans += 1ll * (0ll + up + ml + mr) * (up - mn);
ans %= MOD;
segtree::upd(low, high, up);
minseg::upd(low, high, up);
}
ans %= MOD;
if (ans < 0) ans += MOD;
cout << ans << ln;
}
Compilation message
Main.cpp: In function 'INPUT& operator>>(INPUT&, T&)':
Main.cpp:106:2: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
106 | else if constexpr (is_integral_v<T>) i = in.ReadInt<T>(); return in;
| ^~~~
Main.cpp:106:60: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'else'
106 | else if constexpr (is_integral_v<T>) i = in.ReadInt<T>(); return in;
| ^~~~~~
Main.cpp: In function 'OUTPUT& operator<<(OUTPUT&, T)':
Main.cpp:114:2: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
114 | else if constexpr (is_integral_v<T>) out.WriteInt<T>(i); return out;
| ^~~~
Main.cpp:114:59: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'else'
114 | else if constexpr (is_integral_v<T>) out.WriteInt<T>(i); return out;
| ^~~~~~
Main.cpp: In function 'void segtree::init(int, int, int)':
Main.cpp:181:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
181 | int m = s + e >> 1;
| ~~^~~
Main.cpp: In function 'void segtree::upd(int, int, int, int, int, int)':
Main.cpp:206:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
206 | int m = s + e >> 1;
| ~~^~~
Main.cpp: In function 'node segtree::query(int, int, int, int, int)':
Main.cpp:216:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
216 | int m = s + e >> 1;
| ~~^~~
Main.cpp: In function 'void minseg::init(int, int, int)':
Main.cpp:230:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
230 | int m = s + e >> 1;
| ~~^~~
Main.cpp: In function 'void minseg::upd(int, int, int, int, int, int)':
Main.cpp:243:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
243 | int m = s + e >> 1;
| ~~^~~
Main.cpp: In function 'int minseg::get(int, int, int, int)':
Main.cpp:253:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
253 | int m = s + e >> 1;
| ~~^~~
Main.cpp: In function 'int main()':
Main.cpp:259:35: error: 'class INPUT' has no member named 'tie'
259 | ios::sync_with_stdio(false), cin.tie(0);
| ^~~
Main.cpp: In member function 'void OUTPUT::Flush()':
Main.cpp:77:8: warning: ignoring return value of 'ssize_t write(int, const void*, size_t)' declared with attribute 'warn_unused_result' [-Wunused-result]
77 | write(1, write_buf, write_idx);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
