Submission #1086120

#	Time	Username	Problem	Language	Result	Execution time	Memory
1086120		duytuandao21	Po (COCI21_po)	C++17	20 / 70	16 ms	3272 KiB

Main

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

const int N = 2e5 + 7;
const int inf = 1e9 + 7;
const long long infll = 1e18 + 7;

int n;
int a[N], posMin[N], prePos[N];
pair<int, int> b[N];
int main() 
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        b[i] = make_pair(a[i], i);
    }
    sort (b + 1, b + 1 + n);
    int cnt = 0;
    b[0].first = -1;
    for (int i = 1; i <= n; i++) {
        if (b[i].first != b[i - 1].first) cnt++;
        a[b[i].second] = cnt;
    }
    stack <int> st;
    for (int i = 1; i <= n; i++) {
        while (st.size() > 0 && a[i] <= a[st.top()]) st.pop();
        if (st.size() > 0) posMin[i] = st.top();
        st.push(i);
    }
    int res = 0;
    for (int i = 1; i <= n; i++) {
        if (prePos[a[i]] == 0) res++;
        else {
            if (posMin[i] > prePos[a[i]]) res++;
        }
        prePos[a[i]] = i;
    }
    cout << res;
    return 0;
}

• Subtask 1: 20 / 70