Submission #977914

#	Time	Username	Problem	Language	Result	Execution time	Memory
977914		SmuggingSpun	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	57 / 100	156 ms	33192 KiB

skyscraper

#include<bits/stdc++.h>
#define taskname "skyscraper"
using namespace std;
typedef long long ll;
template<class T>bool minimize(T& a, T b){
	if(a > b){
		a = b;
		return true;
	}
	return false;
}
const int lim = 3e4 + 5;
int n, m, b[lim], p[lim];
namespace sub1{
	void solve(){
		if(m == 2){
			return void(cout << (abs(b[0] - b[1]) % p[0] == 0 ? abs(b[0] - b[1]) / p[0] : -1));
		}
		int ans = (abs(b[0] - b[1]) % p[0] == 0 ? abs(b[0] - b[1]) / p[0] : INT_MAX);
		if(abs(b[0] - b[2]) % p[0] == 0 && abs(b[2] - b[1]) % p[2] == 0){
			minimize(ans, abs(b[0] - b[2]) / p[0] + abs(b[2] - b[1]) / p[2]);
		}
		cout << (ans == INT_MAX ? -1 : ans);
	}
}
namespace sub23{
	const int LIM = 2e3 + 5;
	int d[LIM];
	void solve(){
		priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>>pq;
		memset(d, 0x0f, sizeof(d));
		pq.emplace(d[0] = 0, 0);
		while(!pq.empty()){
			auto [w, u] = pq.top();
			pq.pop();
			if(w == d[u]){
				for(int v = 0; v < m; v++){
					if(abs(b[u] - b[v]) % p[u] == 0 && minimize(d[v], w + abs(b[u] - b[v]) / p[u])){
						pq.emplace(d[v], v);
					}
				}
			}
		}
		cout << (d[1] == d[LIM - 1] ? -1 : d[1]);
	}
}
namespace sub4{
	const int LIM = 2e3 + 5;
	int d[LIM];
	vector<int>pos[LIM];
	void solve(){
		priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>>pq;
		memset(d, 0x0f, sizeof(d));
		pq.emplace(d[b[0]] = 0, b[0]);
		for(int i = 0; i < m; i++){
			pos[b[i]].emplace_back(i);
		}
		while(!pq.empty()){
			auto [w, u] = pq.top();
			pq.pop();
			if(u == b[1]){
				return void(cout << w);
			}
			if(w == d[u]){
				for(int& index : pos[u]){
					for(int v = u - p[index], cnt = 1; v > -1; v -= p[index], cnt++){
						if(minimize(d[v], w + cnt)){
							pq.emplace(d[v], v);
						}
					}
					for(int v = u + p[index], cnt = 1; v < n; v += p[index], cnt++){
						if(minimize(d[v], w + cnt)){
							pq.emplace(d[v], v);
						}
					}
				}
			}
		}
		cout << -1;
	}
}
namespace sub5{
	const int SIZE = 200;
	vector<int>pos[lim];
	vector<vector<int>>e[SIZE];
	int d[lim];
	void solve(){
		for(int i = 1; i < SIZE; i++){
			e[i].resize(i);
		}
		for(int i = 0; i < m; i++){
			pos[b[i]].emplace_back(p[i]);
			for(int j = 1; j < SIZE; j++){
				e[j][b[i] % j].emplace_back(b[i]);
			}
		}
		for(int i = 0; i < n; i++){
			sort(pos[i].begin(), pos[i].end());
			pos[i].resize(unique(pos[i].begin(), pos[i].end()) - pos[i].begin());
		}
		priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>>pq;
		memset(d, 0x0f, sizeof(d));
		pq.emplace(d[b[0]] = 0, 0);
		while(!pq.empty()){
			auto [w, u] = pq.top();
			pq.pop();
			if(u == b[1]){
				return void(cout << w);
			}
			if(w == d[u]){
				for(int& index : pos[u]){
					if(p[index] < SIZE){
						for(int& v : e[p[index]][u % p[index]]){
							if(minimize(d[v], w + abs(v - u) / p[index])){
								pq.emplace(d[v], v);
							}
						}
					}
					else{
						for(int v = u - p[index], cnt = 1; v > -1; v -= p[index], cnt++){
							if(minimize(d[v], w + cnt)){
								pq.emplace(d[v], v);
							}
						}
						for(int v = u + p[index], cnt = 1; v < n; v += p[index], cnt++){
							if(minimize(d[v], w + cnt)){
								pq.emplace(d[v], v);
							}
						}
					}
				}
			}
		}
		cout << -1;
	}
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
	cin >> n >> m;
	for(int i = 0; i < m; i++){
		cin >> b[i] >> p[i];
	}
	if(n <= 10 && m <= 3){
		sub1::solve();
	}
	else if(n <= 2000 && m <= 2000){
		sub23::solve();
	}
	else if(n <= 2000){
		sub4::solve();
	}
	else{
		sub5::solve();
	}
}

Compilation message (stderr)

skyscraper.cpp: In function 'void sub23::solve()':
skyscraper.cpp:34:9: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   34 |    auto [w, u] = pq.top();
      |         ^
skyscraper.cpp: In function 'void sub4::solve()':
skyscraper.cpp:59:9: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   59 |    auto [w, u] = pq.top();
      |         ^
skyscraper.cpp: In function 'void sub5::solve()':
skyscraper.cpp:105:9: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  105 |    auto [w, u] = pq.top();
      |         ^
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:140:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  140 |   freopen(taskname".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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