Submission #65921022

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
using ary = array<int, 2>;
template <typename T>
using vec = vector<T>;
constexpr int N = 2e5 + 5, mod = 998244353;

int main()
{
    ios::sync_with_stdio(false), cin.tie(0);
    int n;
    cin >> n;
    vec<int> a(n + 1);
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    vec<int> l, r;
    for (int i = 1; i <= n; i++) 
    {
        if (i > 1 && i < n)
        {
            if (a[i] > a[i - 1] && a[i] > a[i + 1]) 
                l.push_back(i); 
            if (a[i] < a[i - 1] && a[i] < a[i + 1]) r.push_back(i);
        }
    }
    i64 ans = 0;
    for (int i = 1; i < n; i++)
    {
        if (a[i] < a[i + 1])
        {
            int posl1 = upper_bound(l.begin(), l.end(), i) - l.begin();
            int posr1 = upper_bound(r.begin(), r.end(), i) - r.begin();
            if (posl1 == l.size() || posr1 == r.size()) continue;

            
            int posl2 = upper_bound(l.begin(), l.end(), l[posl1]) - l.begin();
            int posr2 = upper_bound(r.begin(), r.end(), r[posr1]) - r.begin();
            int pos1 = (posl2 == l.size() ? n : l[posl2]);
            int pos2 = (posr2 == r.size() ? n : r[posr2]);
            int L = max(l[posl1], r[posr1]) + 1;
            int R = min(pos1, pos2);
            if (L - i + 1 >= 4) ans += R - L + 1;
        }
    }
    cout << ans;
    return 0;
}

Submission Info

Compile Error

Main.cpp: In function ‘int main()’:
Main.cpp:34:23: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   34 |             if (posl1 == l.size() || posr1 == r.size()) continue;
      |                 ~~~~~~^~~~~~~~~~~
Main.cpp:34:44: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   34 |             if (posl1 == l.size() || posr1 == r.size()) continue;
      |                                      ~~~~~~^~~~~~~~~~~
Main.cpp:39:31: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   39 |             int pos1 = (posl2 == l.size() ? n : l[posl2]);
      |                         ~~~~~~^~~~~~~~~~~
Main.cpp:40:31: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   40 |             int pos2 = (posr2 == r.size() ? n : r[posr2]);
      |                         ~~~~~~^~~~~~~~~~~

Judge Result