Submission #673798

#	Time	Username	Problem	Language	Result	Execution time	Memory
673798		sudheerays123	Lightning Rod (NOI18_lightningrod)	C++17	66 / 100	1339 ms	262144 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define ll long long int
const ll N = 100+5 , INF = 1e18 , MOD = 1e9+7;

bool inside(ll x1 , ll y1 , ll x2 , ll y2){
	return (abs(x2-x1) <= (y2-y1));
}

void solve(){

	ll n;
	cin >> n;

	vector<pair<ll,ll>> a(n+5);
	for(ll i = 1; i <= n; i++) cin >> a[i].first >> a[i].second;

	vector<ll> leftadd(n+5) , leftinclude(n+5,INF);

	for(ll i = 1; i <= n; i++){
		ll last = INF;
		for(ll j = i-1; j >= 1; j--){
			if(!(inside(a[j].first,a[j].second,a[i].first,a[i].second))){
				last = j+1;
				break;
			}
		}
		if(last == INF) last = 1;
		leftadd[i] = last;
	}

	for(ll i = 1; i <= n; i++){
		for(ll j = i+1; j <= n; j++){
			if((inside(a[j].first,a[j].second,a[i].first,a[i].second))){
				leftinclude[j] = min(leftinclude[j],i);
			}
			else break;
		}
	}

	vector<ll> dp(n+5);
	dp[1] = 1;

	for(ll i = 1; i <= n; i++){
		dp[i] = dp[leftadd[i]-1]+1;
		if(leftinclude[i] != INF) dp[i] = min(dp[i],dp[leftinclude[i]]);
	}

	cout << dp[n];
}

int main(){

	fast;

	ll tc = 1;
	// cin >> tc;
	while(tc--) solve();

	return 0;
}

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