Submission #25653

#	Time	Username	Problem	Language	Result	Execution time	Memory
25653		gabrielsimoes	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	57 / 100	1000 ms	3648 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
const int MAXN = 3e4+10;
const ll INF = ll(MAXN)*ll(MAXN)*ll(MAXN);
 
int N, M, X, Y;
vector<int> v[MAXN];
bool ok[MAXN];
ll d[MAXN];
 
void dijkstra() {
	memset(d, -1, sizeof(d));
	d[X] = 0;
	
	while (true) {
		int cur = -1;
		for (int i = 0; i < N; i++)
			if (d[i] != -1 && !ok[i] && (cur == -1 || d[i] < d[cur]))
				cur = i;
		if (cur == -1) return;
		ok[cur] = true;
	
		for (int dx : v[cur]) {
			int cnt = (N - cur)/dx;
			int i = cur + dx*cnt;
			while (i >= 0) {
				if (d[i] == -1 || d[cur] + abs(cnt) < d[i])
					d[i] = d[cur] + abs(cnt);
				i -= dx; cnt--;
			}
		}
	}
}
 
int main()
{
	scanf("%d %d", &N, &M);
	for (int i = 0,a,b; i < M; i++) {
		scanf("%d %d", &a, &b);
		if (i == 0) X = a;
		else if (i == 1) Y = a;
		if (b != 0) v[a].push_back(b);
	}
	
	for (int i = 0; i < N; i++)
		sort(v[i].begin(), v[i].end()),
		v[i].resize(unique(v[i].begin(), v[i].end()) - v[i].begin());
 
	dijkstra();
	printf("%lld\n", d[Y]);
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:39:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &N, &M);
                        ^
skyscraper.cpp:41:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &a, &b);
                         ^

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