Submission #676064

#	Time	Username	Problem	Language	Result	Execution time	Memory
676064		Keshi	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	0 / 100	4 ms	5028 KiB

skyscraper

//In the name of God
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const ll maxn = 2e5 + 100;
const ll mod = 1e9 + 7;
const ll inf = 1e18;

#define fast_io ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define file_io freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout);
#define pb push_back
#define Mp make_pair
#define F first
#define S second
#define Sz(x) int((x).size())
#define all(x) (x).begin(), (x).end()

ll pw(ll a, ll b){
	ll c = 1;
	while(b){
		if(b & 1) c = c * a % mod;
		a = a * a % mod;
		b >>= 1;
	}
	return c;
}

map<int, bool> vis;

int n, m, goal = -1, dis;

bool vs[maxn];

vector<int> vec[maxn];
vector<pii> q, qu;

void add(int v){
	if(0 > v || v >= m || vs[v]) return;
	if(v == goal){
		cout << dis;
		exit(0);
	}
	for(int x : vec[v]){
		vis[(x << 15) | v] = 1;
		q.pb(Mp(v, x));
	}
	return;
}

int main(){
	fast_io;
	
	cin >> m >> n;
	
	for(int i = 0; i < n; i++){
		int v, x;
		if(i == 1) goal = i;
		cin >> v >> x;
		vec[v].pb(x);
	}
	add(0);
	
	while(!q.empty()){
		dis++;
		qu = q;
		q.clear();
		for(pii i : qu){
			int v = i.F, x = i.S;
			add(v - x);
			add(v + x);
			if(v + x < m && !vis[(x << 15) | (v + x)]){
				vis[(x << 15) | (v + x)] = 1;
				q.pb(Mp(v + x, x));
			}
			if(0 < v - x && !vis[(x << 15) | (v - x)]){
				vis[(x << 15) | (v - x)] = 1;
				q.pb(Mp(v - x, x));	
			}
		}
	}
	cout << -1;
	
	return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 12
• Subtask 3: 0 / 14
• Subtask 4: 0 / 21
• Subtask 5: 0 / 43