Submission #68368

#	Time	Username	Problem	Language	Result	Execution time	Memory
68368		thebes	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	57 / 100	1096 ms	97372 KiB

skyscraper

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

const int MN = 30004, MS = 180;
int N, M, S, i, j, src, des, x, y, ent[MN];
struct pir{int f, s, p;}; vector<pir> e[MN]; bitset<MS> pw[MN]; 
pir pr(int f, int s, int p){pir z={f,s,p}; return z;}
struct pq{bool operator()(const pir&i,const pir&j){return(i.s>j.s);}};
priority_queue<pir,vector<pir>,pq> q;

int main(){
	for(scanf("%d%d",&N,&M),S=sqrt(N+0.0);i<M;i++){
		scanf("%d%d",&x,&y);
		if(i == 0) src = x;
		else if(i == 1) des = x;
		if(y >= S){
			for(j=1;x-j*y>=0;j++)
				e[x].push_back(pr(x-j*y,j,-1));
			for(j=1;x+j*y<N;j++)
				e[x].push_back(pr(x+j*y,j,-1));
		}
		else e[x].push_back(pr(x,0,y));
	}
	pir st = {src, 0, -1}; q.push(st);
	while(!q.empty()){
		pir _ = q.top(); q.pop();
		if(_.f == des){printf("%d\n",_.s); return 0;}
		if(_.p == -1){
			if(ent[_.f]) continue;
			else ent[_.f] = 1;
			for(auto v : e[_.f]){
				if(v.p == -1 && !ent[v.f]) q.push(pr(v.f,v.s+_.s,v.p));
				else if(v.p != -1 && !pw[v.f][v.p]) q.push(pr(v.f,v.s+_.s,v.p));
			}
		}
		else{
			if(pw[_.f][_.p]) continue;
			else pw[_.f][_.p] = 1;
			if(!ent[_.f]) q.push(pr(_.f,_.s,-1));
			if(_.f+_.p < N && !pw[_.f+_.p][_.p]) q.push(pr(_.f+_.p,_.s+1,_.p));
			if(_.f-_.p >=0 && !pw[_.f-_.p][_.p]) q.push(pr(_.f-_.p,_.s+1,_.p));
		}
	}
	printf("-1\n");
	return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:12:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(scanf("%d%d",&N,&M),S=sqrt(N+0.0);i<M;i++){
      ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
skyscraper.cpp:13:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&x,&y);
   ~~~~~^~~~~~~~~~~~~~

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