Submission #886815

#	Time	Username	Problem	Language	Result	Execution time	Memory
886815		prohacker	Curtains (NOI23_curtains)	C++14	100 / 100	841 ms	45652 KiB

curtains

#include <bits/stdc++.h>
#define ll long long
#define ld long double

using namespace std;

const int N = 5e5+10;
const int INF = INT_MAX;
const int mod = 1e9+7;
const string NAME = "solve";

int n,m,t;
pair<int,int> edges[N];
vector<pair<int,int>> events[N];
int ans[N];
int tree[4*N],lazy[4*N];

void down(int id, int l, int r) {
    int &t = lazy[id];
    if(t == 0) {
        return;
    }
    tree[id] = max(tree[id],t);
    if(l < r) {
        lazy[id << 1] = max(lazy[id << 1],t);
        lazy[id << 1 | 1] = max(lazy[id << 1 | 1],t);
    }
    t = 0;
}

void update(int u, int v, int val, int id = 1, int l = 1, int r = n) {
    down(id,l,r);
    if(r < u or v < l) {
        return;
    }
    if(u <= l and r <= v) {
        lazy[id] = val;
        down(id,l,r);
        return;
    }
    int mid = l + r >> 1;
    update(u,v,val,id << 1,l,mid);
    update(u,v,val,id << 1 | 1,mid+1,r);
    tree[id] = min(tree[id << 1],tree[id << 1 | 1]);
}

int get(int u, int v, int id = 1, int l = 1, int r = n) {
    down(id,l,r);
    if(r < u or v < l) {
        return mod;
    }
    if(u <= l and r <= v) {
        return tree[id];
    }
    int mid = l + r >> 1;
    return min(get(u,v,id << 1,l,mid),get(u,v,id << 1 | 1,mid+1,r));
}

signed main()
{
    if (fopen((NAME + ".inp").c_str(), "r")) {
        freopen((NAME + ".inp").c_str(), "r", stdin);
        freopen((NAME + ".out").c_str(), "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> m >> t;
    for(int i = 1 ; i <= m ; i++) {
        int l,r; cin >> l >> r;
        edges[i] = {r,l};
    }
    for(int i = 1 ; i <= t ; i++) {
        int l,r; cin >> l >> r;
        events[r].push_back({l,i});
    }
    sort(edges+1,edges+m+1);
    for(int i = 1, j = 1 ; i <= n ; i++) {
        while(j <= m and edges[j].first <= i) {
            update(edges[j].second,edges[j].first,edges[j].second);
            j++;
        }
        for(auto p:events[i]) {
            int val = get(p.first,i);
            if(val >= p.first) {
                ans[p.second] = 1;
            }
        }
    }
    for(int i = 1 ; i <= t ; i++) {
        if(ans[i]) {
            cout << "YES" << '\n';
        }
        else {
            cout << "NO" << '\n';
        }
    }
    return 0;
}

Compilation message (stderr)

curtains.cpp: In function 'void update(int, int, int, int, int, int)':
curtains.cpp:41:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   41 |     int mid = l + r >> 1;
      |               ~~^~~
curtains.cpp: In function 'int get(int, int, int, int, int)':
curtains.cpp:55:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   55 |     int mid = l + r >> 1;
      |               ~~^~~
curtains.cpp: In function 'int main()':
curtains.cpp:62:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |         freopen((NAME + ".inp").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
curtains.cpp:63:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |         freopen((NAME + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 6 / 6
• Subtask 3: 15 / 15
• Subtask 4: 20 / 20
• Subtask 5: 36 / 36
• Subtask 6: 20 / 20