Submission #489267

#	Time	Username	Problem	Language	Result	Execution time	Memory
489267		SirCovidThe19th	Mountain Trek Route (IZhO12_route)	C++17	100 / 100	472 ms	65536 KiB

route

#include <bits/stdc++.h>
using namespace std;

const int mx = 1e6 + 5;

int n, k, A[mx], ans; vector<int> range[mx]; stack<int> stk; 

int main(){
    cin >> n >> k;
    for (int i = 1; i <= n; i++){
        cin >> A[i];
        while (!stk.empty() and A[stk.top()] <= A[i]) stk.pop();
        stk.push(i);
    }
    for (int i = 1; i <= n; i++){
        int mxTop = 0;
        while (!stk.empty()){
            int L = stk.top();
            if (L < i) range[i - L - 1].push_back(min(A[L], A[i]) - mxTop);
            else range[n - (L - i + 1)].push_back(min(A[L], A[i]) - mxTop);
            if (A[L] > A[i]) break;
            mxTop = max(mxTop, A[L]); stk.pop();
        }
        stk.push(i);
    }
    for (long long len = 1; len <= n; len++){
        for (int lim : range[len]){
            if (len * lim >= k) ans += 2 * (k / len), k = 0;
            else ans += 2 * lim, k -= len * lim;
        }
    }
    cout<<ans<<endl;
}

• Subtask 1: 100 / 100