Submission #1110187

#	Time	Username	Problem	Language	Result	Execution time	Memory
1110187		hqminhuwu	Lightning Rod (NOI18_lightningrod)	C++14	100 / 100	1312 ms	262144 KiB

Main

#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair <ll,ll> pll;
typedef pair <int,int> pii;
typedef pair <int,pii> piii;

#define forr(_a,_b,_c) for(int _a = (_b); _a <= int (_c); ++_a)
#define ford(_a,_b,_c) for(int _a = (_b) + 1; _a --> int (_c);)
#define forf(_a,_b,_c) for(int _a = (_b); _a < int (_c); ++_a)
#define st first
#define nd second
#define pb push_back
#define mp make_pair
#define all(x) begin(x),end(x)
#define mask(i) (1LL << (i))
#define bit(x, i) (((x) >> (i)) & 1)
#define bp __builtin_popcountll
#define file "test"

template<class X, class Y>
    bool minz(X &x, const Y &y) {
        if (x > y) {
            x = y;
            return true;
        } return false;
    }
template<class X, class Y>
    bool maxz(X &x, const Y &y) {
        if (x < y) {
            x = y;
            return true;
        } return false;
    }

const int N = 1e7 + 5;
const ll oo = (ll) 1e16;
const ll mod = 1e9 + 7; // 998244353;

int n, a[N], b[N], cnt[N];

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    #ifdef kaguya
        freopen(file".inp", "r", stdin); freopen(file".out", "w", stdout);
    #endif

    cin >> n;

    forr (i, 1, n){
        cin >> a[i] >> b[i];
    }

    int mx = -1;

    forr (i, 1, n){
        if (mx >= a[i] + b[i]){
            cnt[i]++;
        }
        maxz(mx, a[i] + b[i]);
    }

    int mn = mod;

    ford (i, n, 1){
        if (mn <= a[i] - b[i]){
            cnt[i]++;
        }
        minz(mn, a[i] - b[i]);
     //   cout << mn << " " << a[i] - b[i] << endl;
    }

    int res = 0;

    forr (i, 1, n){
        res += (!cnt[i]);
    }

    cout << res << "\n";

    return 0;
}
/*



*/

• 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