Submission #1146565

#	Time	Username	Problem	Language	Result	Execution time	Memory
1146565		agrim_09	Curtains (NOI23_curtains)	C++20	100 / 100	715 ms	85700 KiB

curtains

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
template <class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define endl '\n';
#define fastio ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define py cout << "YES" << endl;
#define pn cout << "NO" << endl;
#define pb push_back
#define int long long
typedef long double lld;
#define double lld
typedef long long ll;
typedef unsigned long long ull;
const ll inf = 1e18;
const ll mod = 1e9+7;
const int N = 2e5;
vector<int>primes = {2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97};

// Check for queue, priorioty_queue, stack, ordered_set solutions
// stack => LIFO (whatever goes in last comes out last)
// queue => FIFO (whatever goes in first comes out first)
// priority_queue => Dynamic queries of minimum/maximum
// ordered_set => set in vector form
//[order_of_key(k) gives number of elements less than k, while find_by_order(i) gives i^th element]

// To comment multiple lines : ctrl + /
// To find and replace : ctrl+H

void judge(){
    srand(time(NULL));
    #ifndef ONLINE_JUDGE
    freopen("1.txt","r",stdin);
    freopen("2.txt","w",stdout);
    freopen("Error.txt", "w", stderr);
    #define debug(x...) cerr << #x <<" = "; _print(x); cerr << endl;
    #else
    #define debug(x...)
    #endif
}

void usaco(string s) {
    freopen((s + ".in").c_str(),"r",stdin);
    freopen((s + ".out").c_str(),"w",stdout);
}

struct node {
    int sum;
    node(int x = 0){
        sum = x;
    }
};
 
struct lazyNode {
    bool is_set = false;  // Flag for set operation
    int set_val = -1*inf;  // Value for the set operation
};

node unite(node a, node b) {
    return node(min(a.sum,b.sum));
} 

class LazySegmentTree {
private:
    vector<node> t;
    vector<lazyNode> lazy;
    int n;
    vector<int>a;
    
    #define mid (start+end)/2
    #define lc x + 1 
    #define rc 2*(mid-start+1)+x 

 
    void build(int x, int start, int end) {
        if (start == end) {
            t[x]= node(-1); 
            return; 
        } 
        build(lc, start, mid);  
        build(rc, mid + 1, end); 
        t[x] = unite(t[lc], t[rc]);  
    }
 
    void push(int x, int start, int end) { // MAKE CHANGES HERE
        if (lazy[x].is_set) {  
            t[x].sum = max(t[x].sum,lazy[x].set_val);
 
            if (start != end) {  
                lazy[lc].is_set = true;
                lazy[rc].is_set = true;
                lazy[lc].set_val = max(lazy[lc].set_val,lazy[x].set_val);
                lazy[rc].set_val = max(lazy[rc].set_val,lazy[x].set_val);
            }
            lazy[x].is_set = false;  
            lazy[x].set_val = -1*inf;
        }
    }
 
    void set(int x, int start, int end, int l, int r, int val) {
        push(x, start, end); 
        
        if(l<=start and end<=r){
            lazy[x].is_set = true;
            lazy[x].set_val = max(lazy[x].set_val,val);
            push(x,start,end);
            return;
        }
 
        if(r<=mid){
            push(rc,mid+1,end);
            set(lc,start,mid,l,r,val);
        }
        else if(mid<l){
            push(lc,start,mid);
            set(rc,mid+1,end,l,r,val);
        }
        else{
            set(lc,start,mid,l,r,val);
            set(rc,mid+1,end,l,r,val);
        }
        t[x] = unite(t[lc], t[rc]); 
    } 
 
    node query(int x, int start, int end, int l, int r) {
        push(x, start, end);  
 
        if (l <= start && end<=r) {
            return t[x];  
        }
        if(r<=mid){
            return query(lc,start,mid,l,r);
        }
        else if(mid<l){
            return query(rc,mid+1,end,l,r);
        }
        else{
            return unite(query(lc,start,mid,l,r),query(rc,mid+1,end,l,r));
        }
    }
 
 
public:
    void build(vector<int>&tmp) {
        n = tmp.size();
        a = tmp;
        t.resize(2 * n);
        lazy.resize(2 * n);
        build(0, 0, n - 1); 
    }
 
    void set(int l, int r) {
        set(0, 0, n - 1, l, r, l);
    }
 
    node query(int l, int r) {
        node result = query(0, 0, n - 1, l, r);
        return result;  
    }
};

signed main(){
    fastio; //judge();
    int n,m,q; cin >> n >> m >> q;
    vector<vector<int>>end(n);
    for(int i = 0,u,v;i<m;i++){
        cin >> u >> v; u--; v--;
        end[v].pb(u);
    }
    vector<vector<pair<int,int>>>queries(n);
    for(int i = 0,u,v;i<q;i++){
        cin >> u >> v; u--; v--;
        queries[v].pb({u,i});
    }
    vector<bool>result(q,false);

    vector<int>tmp(n); LazySegmentTree seg; 
    seg.build(tmp);

    for(int i = 0;i<n;i++){
        for(auto x : end[i]){
            seg.set(x,i);
        }
        for(auto [pos,idx] : queries[i]){
            result[idx] = (seg.query(pos,i).sum==pos);
        }
    }

    for(int i = 0;i<q;i++){
        if(result[i]){
            py;
        }
        else{
            pn;
        }
    }
}

Compilation message (stderr)

curtains.cpp: In function 'void judge()':
curtains.cpp:37:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     freopen("1.txt","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~
curtains.cpp:38:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |     freopen("2.txt","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~
curtains.cpp:39:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |     freopen("Error.txt", "w", stderr);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
curtains.cpp: In function 'void usaco(std::string)':
curtains.cpp:47:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |     freopen((s + ".in").c_str(),"r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
curtains.cpp:48:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |     freopen((s + ".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