#include <bits/stdc++.h>
using namespace std;
struct SegmentTree {
int size;
vector<int> tree;
SegmentTree(int n) {
size = 1;
while (size < n) size *= 2;
tree.assign(2 * size, 0);
}
void add(int pos) {
pos += 1;
int i = size + pos - 1;
tree[i] = pos;
i /= 2;
while (i) {
tree[i] = max(tree[2 * i], tree[2 * i + 1]);
i /= 2;
}
}
int query(int l, int r) {
if (l > r) return 0;
l += size;
r += size;
int res = 0;
while (l <= r) {
if (l % 2 == 1) {
res = max(res, tree[l]);
l++;
}
if (r % 2 == 0) {
res = max(res, tree[r]);
r--;
}
l /= 2;
r /= 2;
}
return res;
}
int prev_one(int pos, int n) {
int res = query(0, pos - 1);
if (res == 0) {
res = query(0, n - 1);
}
return res - 1;
}
};
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
vector<int> l(n);
for (int i = 0; i < n; i++) cin >> l[i];
vector<int> k_score(n, 1);
vector<pair<int, int>> bst;
bst.reserve(n);
for (int i = 0; i < n; i++) {
bst.push_back({i, l[i]});
}
sort(bst.begin(), bst.end(), [](const auto &a, const auto &b) {
return a.second > b.second;
});
SegmentTree seg(n);
vector<int> diff(n + 1, 0);
int x = 10000000;
vector<int> buff;
for (int i = 0; i < n; i++) {
if (bst[i].second < x) {
for (int el : buff) {
seg.add(el);
}
for (int el : buff) {
int prev = seg.prev_one(el, n);
int limit = (el - prev - 1 + n) % n;
if (limit > 0) {
int left = (el - limit + n) % n;
int right = (el - 1 + n) % n;
if (left <= right) {
diff[left] += 1;
diff[right + 1] -= 1;
} else {
diff[0] += 1;
diff[right + 1] -= 1;
diff[left] += 1;
diff[n] -= 1;
}
}
}
x = bst[i].second;
buff.clear();
buff.push_back(bst[i].first);
continue;
}
buff.push_back(bst[i].first);
}
int cur = 0;
for (int i = 0; i < n; i++) {
cur += diff[i];
k_score[i] += cur;
}
cout << *max_element(k_score.begin(), k_score.end()) << '\n';
return 0;
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 | #include <bits/stdc++.h> using namespace std; struct SegmentTree { int size; vector<int> tree; SegmentTree(int n) { size = 1; while (size < n) size *= 2; tree.assign(2 * size, 0); } void add(int pos) { pos += 1; int i = size + pos - 1; tree[i] = pos; i /= 2; while (i) { tree[i] = max(tree[2 * i], tree[2 * i + 1]); i /= 2; } } int query(int l, int r) { if (l > r) return 0; l += size; r += size; int res = 0; while (l <= r) { if (l % 2 == 1) { res = max(res, tree[l]); l++; } if (r % 2 == 0) { res = max(res, tree[r]); r--; } l /= 2; r /= 2; } return res; } int prev_one(int pos, int n) { int res = query(0, pos - 1); if (res == 0) { res = query(0, n - 1); } return res - 1; } }; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int n; cin >> n; vector<int> l(n); for (int i = 0; i < n; i++) cin >> l[i]; vector<int> k_score(n, 1); vector<pair<int, int>> bst; bst.reserve(n); for (int i = 0; i < n; i++) { bst.push_back({i, l[i]}); } sort(bst.begin(), bst.end(), [](const auto &a, const auto &b) { return a.second > b.second; }); SegmentTree seg(n); vector<int> diff(n + 1, 0); int x = 10000000; vector<int> buff; for (int i = 0; i < n; i++) { if (bst[i].second < x) { for (int el : buff) { seg.add(el); } for (int el : buff) { int prev = seg.prev_one(el, n); int limit = (el - prev - 1 + n) % n; if (limit > 0) { int left = (el - limit + n) % n; int right = (el - 1 + n) % n; if (left <= right) { diff[left] += 1; diff[right + 1] -= 1; } else { diff[0] += 1; diff[right + 1] -= 1; diff[left] += 1; diff[n] -= 1; } } } x = bst[i].second; buff.clear(); buff.push_back(bst[i].first); continue; } buff.push_back(bst[i].first); } int cur = 0; for (int i = 0; i < n; i++) { cur += diff[i]; k_score[i] += cur; } cout << *max_element(k_score.begin(), k_score.end()) << '\n'; return 0; } |
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