# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
112125 | _demon_ | Jakarta Skyscrapers (APIO15_skyscraper) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
long longi n,m;
long long a[2009];
long long p[2009];
long long done[2009][2009];
long long dp[2009][2009][3];
vector<long long>v[10009];
long long inf=1000000000000009ll;
long long bt(long long id,long long dog,long long yes){
if(yes==1)return inf;
done[id][dog]=1;
if(id<0 || id>n)return inf;
if(id==a[1])return 0;
long long &ret=dp[id][dog][yes];
if(ret!=-1)return ret;
ret=inf;
if(id+p[dog]<=n && id-p[dog]>0)ret=min(bt(id+p[dog],dog,done[id+p[dog]][dog]),bt(id-p[dog],dog,done[id-p[dog]][dog]))+1;
else if(id+p[dog]<=n) ret=min(ret,bt(id+p[dog],dog,done[id+p[dog]][dog]))+1;
else if(id-p[dog]>0) ret=min(ret,bt(id-p[dog],dog,done[id-p[dog]][dog]))+1;
for(int i=0;i<v[id].size();i++){
long long D=v[id][i];
ret=min(ret,bt(id,D,done[id][D]));
}
return ret;
}
int main(){
memset(dp,-1,sizeof(dp));
cin>>n>>m;
for(int i=0;i<m;i++){
cin>>a[i]>>p[i];
v[a[i]].push_back(i);
}
long long x=bt(a[0],0,0);
if(x!=inf) cout<<x<<endl;
else cout<<-1<<endl;
}