Submission #143680

#	Time	Username	Problem	Language	Result	Execution time	Memory
143680		MladenP	Money (IZhO17_money)	C++17	0 / 100	2 ms	376 KiB

money

#include <bits/stdc++.h>
#define MAXN 1000010
#define pii pair<int,int>
#define pb push_back
#define fi first
#define se second
using namespace std;
int a[MAXN], b[MAXN], inv[MAXN], N, l, r;
int L[MAXN], R[MAXN];
vector<pii> seg;
int main() {
    cin >> N;
    for(int i = 1; i <= N; i++) cin >> a[i];
    for(int i = 1; i <= N; i++) b[i-1] = a[i];
    sort(b, b+N);
    for(int i = 0; i < N; i++) inv[b[i]] = i+1;
    for(int i = 1; i <= N; i++) a[i] = inv[a[i]];
    l = r = a[1];
    for(int i = 2; i <= N+1; i++) {
        if(a[i] == r+1) {
            r++;
        } else {
            seg.pb({l, r});
            l = r = a[i];
        }
    }
    int rez = 0;
    R[N+1] = N+1;
    while(!seg.empty()) {
        pii vrh = seg.back(); seg.pop_back();
        l = vrh.fi, r = vrh.se;
        if(R[r+1]) r = R[r+1];
        if(L[l-1]) l = L[l-1];
        while(!seg.empty()) {
            pii vrh = seg.back();
            if(vrh.se+1 == l) {
                l = vrh.fi;
                seg.pop_back();
            } else break;
        }
        if(r != N+1) {
            L[r] = l; R[l] = r;
            rez++;
        }
    }
    cout << rez;
    return 0;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 16
• Subtask 3: 0 / 20
• Subtask 4: 0 / 55