Submission #328587

#	Time	Username	Problem	Language	Result	Execution time	Memory
328587		wind_reaper	Lightning Rod (NOI18_lightningrod)	C++17	4 / 100	511 ms	116060 KiB

Main

// #define _GLIBCXX_DEBUG
// #pragma GCC optimize "trapv"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <chrono>
#include <stdio.h>
#include <cstdlib>
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")

using namespace std;
using namespace __gnu_pbds;
using namespace chrono;

#define pb push_back 
#define f first
#define s second
#define min3(a, b, c) min(min(a, b), c)
#define max3(a, b, c) max(max(a, b), c)
#define all(v) v.begin(), v.end()

typedef long long ll;
typedef double ld;
typedef long double lld;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<pii> vpi;
typedef vector<pll> vpl;

template <class T> using ordered_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;

// const int INF = 1e9;
const ll INF = LLONG_MAX;
const ll mod = 1000000007;

// const ll mod = 998244353;
int BUF=100000;
int buf_readed;
int buf_index;
char buffer[100000];
 
void my_init(){
    buf_index=buf_readed=0;
}
/*****************************************/
char my_getchar(){
    char x;
    if(buf_index==buf_readed){
        buf_index=0;
        buf_readed=fread(buffer,1,BUF,stdin);
    }   
    x=buffer[buf_index];
    buf_index++;
    return x;
}
/*************************************/
int getInt(){
    int r=0;
    char c;
    int sign=1;
    while(1){
        c=my_getchar();
        if(c=='-')
            sign=-1;
 
        if((c>='0' && c<='9')){
            r=(c-'0');
            break;
        }
    }
    while(1){
        c=my_getchar();
            if(!(c>='0' && c<='9'))
                break;
        r=r*10+(c-'0');
    }
    return sign*r;
}

vpi a;
inline bool covers(int i, int j){
    if(abs(a[i].f - a[j].f) <= a[i].s - a[j].s)
        return true;

    return false;
}
void solve(int tc){
    int n;
    cin >> n; 

    a.resize(n);
    for(int i = 0; i < n; i++){
        a[i].f = getInt(); a[i].s = getInt();
    }

    stack<int> r;
    r.push(0); 
    for(int i = 1; i < n; i++){
        if(covers(r.top(), i)) continue;

        while(!r.empty() && covers(i, r.top())) 
            r.pop();

        r.push(i);
    }

    cout << r.size() << '\n';
}


int main(){
    ios_base::sync_with_stdio(NULL);
    cin.tie(NULL);

    #ifdef LOCAL
        auto begin = high_resolution_clock::now();
    #endif
    my_init();
    int tc = 1;
    // cin >> tc; 
    for (int t = 0; t < tc; t++) solve(t);
    
    #ifdef LOCAL 
        auto end = high_resolution_clock::now();
        cout << fixed << setprecision(4) << "Execution Time: " << duration_cast<duration<double>>(end - begin).count() << "seconds" << endl;
    #endif
    return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 0 / 7
• Subtask 3: 0 / 12
• Subtask 4: 0 / 21
• Subtask 5: 0 / 26
• Subtask 6: 0 / 10
• Subtask 7: 0 / 20