#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(long long i=0;i<(long long)(n);i++)
#define REP(i,k,n) for(long long i=k;i<(long long)(n);i++)
#define all(a) a.begin(),a.end()
#define pb emplace_back
#define eb emplace_back
#define lb(v,k) (lower_bound(all(v),k)-v.begin())
#define ub(v,k) (upper_bound(all(v),k)-v.begin())
#define fi first
#define se second
#define pi M_PI
#define PQ(T) priority_queue<T>
#define SPQ(T) priority_queue<T,vector<T>,greater<T>>
#define dame(a) {out(a);return 0;}
#define decimal cout<<fixed<<setprecision(15);
#define dupli(a) a.erase(unique(all(a)),a.end())
typedef long long ll;
typedef pair<ll,ll> P;
typedef tuple<ll,ll,ll> PP;
typedef tuple<ll,ll,ll,ll> PPP;
typedef multiset<ll> S;
using vi=vector<ll>;
using vvi=vector<vi>;
using vvvi=vector<vvi>;
using vvvvi=vector<vvvi>;
using vp=vector<P>;
using vvp=vector<vp>;
using vb=vector<bool>;
using vvb=vector<vb>;
const ll inf=1001001001001001001;
const ll INF=1001001001;
const ll mod=1000000007;
const double eps=1e-10;
template<class T> bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<class T> bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<class T> void out(T a){cout<<a<<'\n';}
template<class T> void outp(T a){cout<<'('<<a.fi<<','<<a.se<<')'<<'\n';}
template<class T> void outvp(T v){rep(i,v.size())cout<<'('<<v[i].fi<<','<<v[i].se<<')';cout<<'\n';}
template<class T> void outvvp(T v){rep(i,v.size())outvp(v[i]);}
template<class T> void outv(T v){rep(i,v.size()){if(i)cout<<' ';cout<<v[i];}cout<<'\n';}
template<class T> void outvv(T v){rep(i,v.size())outv(v[i]);}
template<class T> bool isin(T x,T l,T r){return (l)<=(x)&&(x)<=(r);}
template<class T> void yesno(T b){if(b)out("yes");else out("no");}
template<class T> void YesNo(T b){if(b)out("Yes");else out("No");}
template<class T> void YESNO(T b){if(b)out("YES");else out("NO");}
template<class T> void noyes(T b){if(b)out("no");else out("yes");}
template<class T> void NoYes(T b){if(b)out("No");else out("Yes");}
template<class T> void NOYES(T b){if(b)out("NO");else out("YES");}
void outs(ll a,ll b){if(a>=inf-100)out(b);else out(a);}
ll gcd(ll a,ll b){if(b==0)return a;return gcd(b,a%b);}
ll modpow(ll a,ll b){ll res=1;a%=mod;while(b){if(b&1)res=res*a%mod;a=a*a%mod;b>>=1;}return res;}
ll k=0;
int main(){
ll n,m;cin>>n>>m;
vvi v(n);
ll s,g;
rep(i,m){
ll a,b;cin>>a>>b;
if(i==0)s=a;
if(i==1)g=a;
v[a].pb(b);
}
vvi dis(n,vi(k+1,inf));
SPQ(PP) pq;
dis[s][0]=0;
pq.emplace(0,s,0);
while(!pq.empty()){
auto t=pq.top();pq.pop();
ll cost,i,j;
tie(cost,i,j)=t;
if(i==g)dame(cost);
if(dis[i][j]!=cost)continue;
if(j){
if(i+j<n)if(chmin(dis[i+j][j],cost+1))pq.emplace(cost+1,i+j,j);
if(i-j>=0)if(chmin(dis[i-j][j],cost+1))pq.emplace(cost+1,i-j,j);
if(chmin(dis[i][0],cost))pq.emplace(cost,i,0);
}
else{
for(ll x:v[i]){
if(x<=k)if(chmin(dis[i][x],cost))pq.emplace(cost,i,x);
else{
for(ll u=1;u*x+i<n;u++)if(chmin(dis[u*x+i][0],cost+u))pq.emplace(cost+u,u*x+i,0);
for(ll u=1;i-u*x>=0;u++)if(chmin(dis[i-u*x][0],cost+u))pq.emplace(cost+u,i-u*x,0);
}
}
}
}
out(-1);
}
Compilation message
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:81:19: warning: suggest explicit braces to avoid ambiguous 'else' [-Wdangling-else]
if(x<=k)if(chmin(dis[i][x],cost))pq.emplace(cost,i,x);
^
skyscraper.cpp:72:9: warning: 'g' may be used uninitialized in this function [-Wmaybe-uninitialized]
if(i==g)dame(cost);
^~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
256 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
4 ms |
256 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
