Submission #874874

#	Time	Username	Problem	Language	Result	Execution time	Memory
874874		tsumondai	Osumnjičeni (COCI21_osumnjiceni)	C++14	110 / 110	242 ms	50256 KiB

Main

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

#define int long long
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define foru(i, l, r) for(int i = l; i <= r; i++)
#define ford(i, r, l) for(int i = r; i >= l; i--)
#define __TIME  (1.0 * clock() / CLOCKS_PER_SEC)

typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<ii, ii> iiii;
 
const int N = 2e5 + 5, LOG=18;
 
const int oo = 1e18, mod = 1e9 + 7;
 
int n, m, k, q, lef[N], rig[N], par[N][LOG];
set<ii> st;
vector<int> arr;

bool can_insert(int ind) {
    if (st.empty()) return 1;
    auto it=st.lower_bound({lef[ind], 0});
    int nxt=it->second;
    if (lef[ind]<=lef[nxt] && lef[nxt]<=rig[ind]) return 0;
    if (it!=st.begin()) {
        it--;
        int prv=it->second;
        if (lef[prv]<=lef[ind] && lef[ind]<=rig[prv]) return 0;
    }
    return 1;
}

void precalc() {
    int lim=0;
    foru(i,1,n) {
        if (lim<i) {
            st.clear();
            lim=i;
            st.insert({lef[i], i});
        }
        while (lim+1<=n && can_insert(lim+1)) {
            lim++;
            st.insert({lef[lim], lim});
        }
        par[i][0]=lim+1;
        st.erase({lef[i], i});
    }
    par[n+1][0]=n+1;
    foru(i,1,LOG-1) {
        foru(j,1,n+1) {
            par[j][i]=par[par[j][i-1]][i-1];
        }
    }
}

int query(int a, int b) {
    int res=0;
    ford(i, LOG-1, 0) {
        if (par[a][i]<=b) {
            a=par[a][i];
            res+=1<<i;
        }
    }
    return res+1;
}

void process() {
    cin >> n;
    foru(i,1,n) {
        cin >> lef[i] >> rig[i];
    }
    precalc();
    cin >> q;
    foru(i,1,q) {
        int a, b;
        cin >> a >> b;
        cout << query(a,b) << '\n';
    }
    return;
}

signed main() {
    cin.tie(0)->sync_with_stdio(false);
    //freopen(".inp", "r", stdin);
    //freopen(".out", "w", stdout);
    process();
    cerr << "Time elapsed: " << __TIME << " s.\n";
    return 0;
}

/*
Xét các trường hợp đặc biệt
Kiểm tra lại input/output
Cố gắng trâu
Lật ngược bài toán
Calm down and get VOI 
Flow:

*/

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 50 / 50