Submission #1303199

#	Time	Username	Problem	Language	Result	Execution time	Memory
1303199		trandangquang	Lightning Rod (NOI18_lightningrod)	C++20	100 / 100	426 ms	76160 KiB

Main

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

#define foru(i,a,b) for(int i=(a); i<=(b); ++i)
#define ford(i,a,b) for(int i=(a); i>=(b); --i)
#define rep(i,a) for(int i=0; i<(a); ++i)
#define sz(a) (int)(a).size()
#define all(a) (a).begin(),(a).end()
#define bit(s,i) (((s)>>(i))&1)
#define ii pair<int,int>
#define vi vector<int>
#define vii vector<ii>
#define fi first
#define se second
#define ll long long
#define eb emplace_back
#define pb push_back
#define __builtin_popcount __builtin_popcountll
#define _ << " " <<

template <class X, class Y> bool maxi(X &x, Y y){return x<y?x=y,true:false;}
template <class X, class Y> bool mini(X &x, Y y){return x>y?x=y,true:false;}

const int N=1e7+5;

int n;
ii st[N]; int top;

bool cover(ii u, ii v){
    return abs(u.fi-v.fi)<=u.se-v.se;
}

int read(){
    int x=0;
    char c;
    while(true){
        c=getchar();
        if(c<'0'||c>'9') break;
        x=x*10+c-'0';
    }
    return x;
}

ii tmp;
void solve(){
    n=read();
    foru(i,1,n){
        tmp.fi=read(); tmp.se=read();
        if(top && cover(st[top],tmp)) continue;
        while(top && cover(tmp,st[top])) --top;
        st[++top]=tmp;
    }
    cout<<top<<'\n';
}

int32_t main(){
    #define task "test"
    if(fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    cin.tie(0)->sync_with_stdio(0);

    int tc=1; //cin>>tc;
    foru(i,1,tc){
        solve();
    }
}

Compilation message (stderr)

Main.cpp: In function 'int32_t main()':
Main.cpp:59:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:60:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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