#include<bits/stdc++.h>
using namespace std;
const int inf = 1e9;
int main()
{
ios::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
int n, m;
cin >> n >> m;
int dist[n][m];
for(int i = 0; i < n; i ++)
for(int j = 0; j < m ; j++)
dist[i][j] = inf;
vector<int> L[n];
int p[m], b[m];
for(int i = 0; i < m; i ++)
{
cin >> b[i] >> p[i];
L[b[i]].push_back(i);
}
int cnt[n] = {};
deque<pair<int,int> > Q;
Q.push_back({b[0], 0});
dist[b[0]][0] = 0;
while(Q.size())
{
int f = Q.front().first, s = Q.front().second;
Q.pop_front();
// cerr << f << ' ' << s << ' ' << dist[f][s] << endl;
if(cnt[f] <= 1000) {
for(int res : L[f])
if(dist[f][s] < dist[f][res])
{
dist[f][res] = dist[f][s];
Q.push_front({f, res});
}
cnt[f]++;
}
L[f].clear();
if(f + p[s] < n && dist[f][s] + 1 < dist[f + p[s]][s])
{
dist[f + p[s]][s] = dist[f][s] + 1;
Q.push_front({f + p[s], s});
}
if(f - p[s] >= 0 && dist[f][s] + 1 < dist[f - p[s]][s])
{
dist[f - p[s]][s] = dist[f][s] + 1;
Q.push_front({f - p[s], s});
}
}
if(dist[b[1]][1] == inf)
cout << -1 << endl;
else
cout << dist[b[1]][1] << endl;
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
344 KB |
Output is correct |
| 5 |
Correct |
0 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
348 KB |
Output is correct |
| 7 |
Correct |
0 ms |
344 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
1 ms |
344 KB |
Output is correct |
| 4 |
Correct |
1 ms |
344 KB |
Output is correct |
| 5 |
Correct |
0 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
348 KB |
Output is correct |
| 7 |
Correct |
0 ms |
348 KB |
Output is correct |
| 8 |
Correct |
1 ms |
348 KB |
Output is correct |
| 9 |
Correct |
0 ms |
348 KB |
Output is correct |
| 10 |
Incorrect |
0 ms |
604 KB |
Output isn't correct |
| 11 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
1 ms |
344 KB |
Output is correct |
| 3 |
Correct |
1 ms |
348 KB |
Output is correct |
| 4 |
Correct |
1 ms |
348 KB |
Output is correct |
| 5 |
Correct |
0 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
348 KB |
Output is correct |
| 7 |
Correct |
1 ms |
348 KB |
Output is correct |
| 8 |
Correct |
0 ms |
348 KB |
Output is correct |
| 9 |
Correct |
0 ms |
348 KB |
Output is correct |
| 10 |
Incorrect |
0 ms |
600 KB |
Output isn't correct |
| 11 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Correct |
1 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
348 KB |
Output is correct |
| 7 |
Correct |
0 ms |
348 KB |
Output is correct |
| 8 |
Correct |
0 ms |
348 KB |
Output is correct |
| 9 |
Correct |
0 ms |
348 KB |
Output is correct |
| 10 |
Incorrect |
0 ms |
604 KB |
Output isn't correct |
| 11 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Correct |
0 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
348 KB |
Output is correct |
| 7 |
Correct |
0 ms |
348 KB |
Output is correct |
| 8 |
Correct |
0 ms |
348 KB |
Output is correct |
| 9 |
Correct |
0 ms |
348 KB |
Output is correct |
| 10 |
Incorrect |
0 ms |
604 KB |
Output isn't correct |
| 11 |
Halted |
0 ms |
0 KB |
- |
