ComplexCode/cf5e.cpp at master · Mithril0rd/ComplexCode · GitHub

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#include <cstdio>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
	int n;
    scanf("%d", &n);

    vector<int> height(n);
    for (int i = 0; i < n; i++) scanf("%d", &(height[i]));
    vector<int>::iterator highest = max_element(height.begin(), height.end());
      vector<int> num(highest, height.end());
    num.reserve(n);
    copy(height.begin(), highest, num.end());

	vector<int> left(n, -1);
    for (int i = 1; i < n; i++) {
        int p = i - 1;
        while (num[i] > num[p]) p = left[p];
        left[i] = num[i] == num[p] ? left[p] : p;
    }
	vector<int> right(n, n);
    vector<int> same(n, 0);
    for (int i = n - 2; i >= 0; i--) {
        int p = i + 1;
        while (p < n && num[i] > num[p]) p = right[p];

        if (p >= n) {
            right[i] = p;
            continue;
        }

        right[i] = num[i] == num[p] ? right[p] : p;
        same[i] = num[i] == num[p] ? same[p] + 1 : 0;
    }
	for (int i = 0; i < n; ++i) {
		printf("%d %d %d\n", left[i], right[i], same[i]);
	}
    long long ans = 0;
    for (int i = 0; i < n; i++) {
        if (left[i] >= 0) ans += 1;
        if (right[i] < n) ans += 1;
        if (right[i] >= n && left[i] > 0) ans += 1;
        ans += same[i];
    }

    printf("%I64d\n", ans);
    return 0;
}