#include <bits/stdc++.h>
using namespace std;
const int N=3e4+9;
const int oo=1e9+9;
typedef pair <int,int> ii;
typedef pair <int,ii> iii;
int can,n,m,a[N],p[N],f[N][176];
bool First[N],check[N][176];
vector <int> num[N];
queue <iii> q;
void update(int x,int dist,int val)
{
if (f[x][dist]>val)
{
f[x][dist]=val;
q.push({val,{x,dist}});
}
if (num[x].size()==0||dist==0) return;
update(x,0,val);
}
int solve()
{
if (p[1]>=can)
{
f[1][0]=0;
q.push({0,{1,0}});
}
else
{
f[1][p[1]]=0;
q.push({0,{1,p[1]}});
}
// cout<<f[1][0]<<endl;
int val,x,dist;
// for (int i=0;i<=can;i++)
// {
// //res=min(res,f[a[n]][i]);
// cout<<f[a[n]][i]<<endl;
// }
while (!q.empty())
{
val=q.front().first;
x=q.front().second.first;
dist=q.front().second.second;
q.pop();
if (f[x][dist]!=val) continue;
if (!First[x])
{
First[x]=true;
for (int i=0;i<can;i++)
if (check[x][i]||i==0) update(x,i,val);
}
if (dist!=0)
{
if (x+dist<=n) update(x+dist,dist,f[x][dist]+1);
if (x-dist>=1) update(x-dist,dist,f[x][dist]+1);
continue;
}
for (int xnew:num[x])
{
int dem=0;
for (int i=x;i<=n;i+=p[xnew])
{
update(i,0,dem++);
}
dem=0;
for (int i=x;i>=1;i-=p[xnew])
update(i,0,dem++);
// f[i][0]=min(f[i][0],dem++);
}
}
// cout<<f[5][1]<<"sdsd"<<endl;
int res=oo;
//cout<<f[1][2]<<endl;
for (int i=0;i<=can;i++)
{
res=min(res,f[a[2]][i]);
// cout<<f[a[2]][i]<<endl;
}
return res;
}
signed main()
{
ios::sync_with_stdio(false);
cin.tie(0);
// freopen("test.inp","r",stdin);
cin>>n>>m;
can=sqrt(n);
for (int i=0;i<=n;i++)
for (int j=0;j<=can;j++)
{
f[i][j]=oo;
// cout<<i<<" "<<j<<" "<<f[i][j]<<" "<<oo<<endl;
}
// return 0;
//cout<<f[4][0]<<endl;
for (int i=1;i<=m;i++)
{
cin>>a[i]>>p[i];
a[i]++;
if (p[i]>=can) num[a[i]].push_back(i);
else check[a[i]][p[i]]=true;
// f[a[i]][0]=0;
// q.push({0,{a[i],0}});
// }
// else
// {
// f[a[i]][p[i]]=0;
// q.push({0,{a[i],p[i]}});
// }
}
cout<<solve();
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
972 KB |
Output is correct |
2 |
Correct |
1 ms |
1024 KB |
Output is correct |
3 |
Correct |
1 ms |
1032 KB |
Output is correct |
4 |
Incorrect |
1 ms |
972 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
1024 KB |
Output is correct |
2 |
Correct |
1 ms |
972 KB |
Output is correct |
3 |
Correct |
1 ms |
972 KB |
Output is correct |
4 |
Incorrect |
1 ms |
1028 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
972 KB |
Output is correct |
2 |
Correct |
1 ms |
1004 KB |
Output is correct |
3 |
Correct |
1 ms |
972 KB |
Output is correct |
4 |
Incorrect |
1 ms |
972 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
1032 KB |
Output is correct |
2 |
Correct |
1 ms |
972 KB |
Output is correct |
3 |
Correct |
1 ms |
972 KB |
Output is correct |
4 |
Incorrect |
1 ms |
972 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
1024 KB |
Output is correct |
2 |
Correct |
1 ms |
972 KB |
Output is correct |
3 |
Correct |
1 ms |
972 KB |
Output is correct |
4 |
Incorrect |
1 ms |
972 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |