Submission #984767

#	Time	Username	Problem	Language	Result	Execution time	Memory
984767		Nurislam	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	10 / 100	3 ms	2908 KiB

skyscraper

///*                                                    __                    __                        __                    */
///*        ======     _      /| /|  __   _            /   |  |   /|  |   *  |    |  |  | /   /| |\  | /   |  |  * | /        */
///* \-       ||  |_| |_     / |/ | |  | |_  |-        |   |--|  /-|  |   |  \ \  |==|  |-   /=| | \ | |   |--|  | |-         */
///*          ||  | | |_    /     | |__|  _| |_        \__ |  | /  |  |__ |  __|  |  |  | \ /  | |  \| \__ |  |  | | \        */
///* 
// autor :: Rick Prime
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define int long long
#define Mp make_pair
#define double double long
typedef vector<int> vi;
typedef vector<double> vd;
typedef pair<int,int> pii;
typedef vector<pii> vii;
const int N = 1e6, inf = 2e18, mod = 1e9+7;

void solve(){
	int n, m;
	cin >> n >> m;
	vii v(m);
	for(auto &[i, j]:v)cin >> i >> j;
	int dp[n];
	for(int &i:dp)i = inf;
	dp[v[0].ff] = 0;
	vi r[n];
	for(auto [i, j]:v){r[i].pb(j);}
	priority_queue<pii> q;
	q.push({v[0].ss, v[0].ff});
	int dp2[n][3001];
	for(auto &i:dp2)for(auto &j:i)j = inf;
	bool us[n]{};
	while(!q.empty()){
		auto [p, b] = q.top();
		q.pop();
		for(int x = b, cst = 0; x < n; x+=p, cst++){
			if(dp2[x][p] <= dp[b] + cst)break;
			dp[x] = min(dp[x], dp[b] + cst);
			dp2[x][b] = dp[b] + cst;
			if(!us[x]){
				us[x] = 1;
				for(auto i:r[x])q.push({i, x});
			}
		}
		for(int x = b, cst = 0; x >= 0; x-=p, cst++){
			if(dp2[x][p] <= dp[b] + cst)break;
			dp[x] = min(dp[x], dp[b] + cst);
			dp2[x][b] = dp[b] + cst;
			if(!us[x]){
				us[x] = 1;
				for(auto i:r[x])q.push({i, x});
			}
		}
	}
	//for(auto i:dp)cout << i << ' ';
	//cout << '\n';
	cout << (dp[v[1].ff]==inf?-1:dp[v[1].ff]) << '\n';
}
 
signed main(){
	ios_base::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
	int test = 1;
	//cin >> test;
	while(test--){
		solve();
	}
}
 
 
 
 
 
 
 
 
 
 
 
 
 

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