Submission #1026333

#	Time	Username	Problem	Language	Result	Execution time	Memory
1026333		rsinventor	Global Warming (NOI13_gw)	C++17	19 / 40	724 ms	65536 KiB

gw

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector <vector<int>> vvi;
typedef vector<bool> vb;
typedef vector <vector<bool>> vvb;
typedef vector <string> vs;
typedef vector<char> vc;
typedef vector <vector<char>> vvc;
typedef pair<int, int> pii;
typedef vector <pii> vpii;

#define all(a) (a).begin(), (a).end()
#define pb push_back
#define endl "\n"

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

//    freopen("warming.in", "r", stdin);
//    freopen("warming.out", "w", stdout);
    
    int n;
    cin >> n;
    vi h(n);
    set<int> sh;
    vpii sh2(n);
    for(int i = 0; i < n; i++) {
        cin >> h[i];
        sh2[i].first = h[i];
        sh2[i].second = i;
        sh.insert(h[i]);
    }
    sort(all(sh2));

    int mx_islands = 0;
    if(sh.size()<1000) {
        sh.insert(0);
        for(int v : sh) {
            int islands = 0;
            for(int i = 0; i < n; i++) {
                if(max(0, h[i]-v)>0 && (i==0 || max(0, h[i-1]-v)==0)) islands++;
            }
            mx_islands = max(mx_islands, islands);
        }
    } else {
        int islands = 0;
        mx_islands = 0;
        for(int i = 0; i < n; i++) {
            if(max(0, h[i])>0 && (i==0 || max(0, h[i-1])==0)) islands++;
        }
        mx_islands = max(mx_islands, islands);
        for(int i = 0; i < n; i++) {
            if(sh2[i].first==sh2[i-1].first && abs(sh2[i].second-sh2[i-1].second)==1) continue;
            int s = sh2[i].second;
            int e = sh2[i].second;
            while(e+1<n && h[e] == h[e+1]) e++;
            if(s==0 && e == n-1) {
                islands = 0;
            } else if(s==0 && h[e+1]<h[e]) {
                islands--;
            } else if(e==n-1 && h[s-1]<h[s]) {
                islands--;
            } else {
                if(h[s-1]>h[s] && h[e+1]>h[e]) {
                    islands++;
                    mx_islands = max(mx_islands, islands);
                } else if(h[s-1]<h[s] && h[e+1]<h[e]) {
                    islands--;
                }
            }
        }
        mx_islands = max(mx_islands, islands);
    }
    
    cout << mx_islands << endl;


    return 0;
}

• Subtask 1: 6 / 6
• Subtask 2: 6 / 6
• Subtask 3: 7 / 7
• Subtask 4: 0 / 10
• Subtask 5: 0 / 11