Submission #563563

#	Time	Username	Problem	Language	Result	Execution time	Memory
563563		myrcella	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	374 ms	112380 KiB

skyscraper

//by szh
#include<bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define pb push_back
#define debug(x) cerr<<#x<<"="<<x<<endl
#define pq priority_queue
#define inf 0x3f
#define rep(i,a,b) for (int i=a;i<(b);i++)
#define MP make_pair
#define SZ(x) (int(x.size()))
#define ll long long
#define mod 1000000007
#define ALL(x) x.begin(),x.end()
void inc(int &a,int b) {a=(a+b)%mod;}
void dec(int &a,int b) {a=(a-b+mod)%mod;}
int lowbit(int x) {return x&(-x);}
ll p0w(ll base,ll p) {ll ret=1;while(p>0){if (p%2ll==1ll) ret=ret*base%mod;base=base*base%mod;p/=2ll;}return ret;}

const int maxn = 3e4+10;

int n,m;
vector <int> power[maxn];
deque <pair<int,pii>> q;
bitset <maxn> vis[maxn];

int main() {
//	freopen("input.txt","r",stdin);	
	std::ios::sync_with_stdio(false);cin.tie();
	cin>>n>>m;
	int des;
	rep(i,0,m) {
		int x,y;
		cin>>x>>y;
		power[x].pb(y);
		if (i==0) q.push_back({0,{x,y}}); 
		if (i==1) des=x;
	}
	while (!q.empty()) {
		int d = q.front().fi;
		int x = q.front().se.fi, y = q.front().se.se;
		q.pop_front();
		if (vis[x][y]==1) continue;
//		cout<<x<<" "<<y<<endl;
		vis[x][y] = 1;
		if (x==des) {
			cout<<d;
			return 0;
		}
		if (x+y<n and vis[x+y][y]==0) q.push_back({d+1,{x+y,y}});
		if (x-y>=0 and vis[x-y][y]==0) q.push_back({d+1,{x-y,y}});
		for (auto it:power[x]) {
			if (vis[x][it]==0) q.push_front({d,{x,it}});
		}
	}
	cout<<-1;
	return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:50:3: warning: 'des' may be used uninitialized in this function [-Wmaybe-uninitialized]
   50 |   if (x==des) {
      |   ^~

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