제출 #33758

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
33758		sinhriv	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	57 / 100	1000 ms	40536 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;

const int N = 30030;
const int base = 150;

int n, m;
int f[N][base];
int d[N][base];
vector < int > doges[N];

bool minimize(int &u, int v){
	if(u > v){
		u = v;
		return true;
	}
	return false;
}

int main(){
	if(fopen("1.inp", "r")){
		freopen("1.inp", "r", stdin);
	}

	scanf("%d%d", &n, &m);

	int start = -1, finish = -1;

	for(int i = 1; i <= m; ++i){
		int u, v;
		scanf("%d%d", &u, &v);

		if(start == -1){
			start = u;
		}
		else if(finish == -1){
			finish = u;
		}

		doges[u].push_back(v);
	}

	#define Data pair < int, pair < int, int > >

	priority_queue < Data, vector < Data >, greater < Data > > heap;

	memset(f, 60, sizeof f);
	f[start][0] = 0;

	heap.emplace(0, make_pair(start, 0));
	while(!heap.empty()){
		int u = heap.top().second.first;
		int x = heap.top().second.second;
		heap.pop();

		if(d[u][x] == 1) continue;
		d[u][x] = 1;


		if(u == finish){
			cout << f[u][x];
			return 0;
		}

		if(u - x >= 0){
			if(minimize(f[u - x][x], f[u][x] + 1)){
				heap.emplace(f[u - x][x], make_pair(u - x, x));
			}
		}
		if(u + x < n){
			if(minimize(f[u + x][x], f[u][x] + 1)){
				heap.emplace(f[u + x][x], make_pair(u + x, x));
			}
		}
		
		for(int val : doges[u]){
			if(val < base){
				if(u - val >= 0){
					if(minimize(f[u - val][val], f[u][x] + 1)){
						heap.emplace(f[u - val][val], make_pair(u - val, val));
					}
				}
				if(u + val < n){
					if(minimize(f[u + val][val], f[u][x] + 1)){
						heap.emplace(f[u + val][val], make_pair(u + val, val));
					}
				}
			}
			else{
				for(int t = 1; t < N / base; ++t){
					if(u - t * val < 0 && u + t * val >= n) break;
					if(u - t * val >= 0){
						if(minimize(f[u - t * val][0], f[u][x] + t)){
							heap.emplace(f[u - t * val][0], make_pair(u - t * val, 0));
						}
					}
					if(u + t * val < n){
						if(minimize(f[u + t * val][0], f[u][x] + t)){
							heap.emplace(f[u + t * val][0], make_pair(u + t * val, 0));
						}
					}
				}
			}
		}
	}
	cout << -1;
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:23:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen("1.inp", "r", stdin);
                               ^
skyscraper.cpp:26:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
                       ^
skyscraper.cpp:32:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &u, &v);
                        ^

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