#include <bits/stdc++.h>
using namespace std;
const int INF = 1e8;
const int mxN = 30005;
int n, m;
vector<vector<int>> adj(mxN);
int b[mxN];
int f[mxN][200];
signed main() {
#define taskname ""
if(fopen(taskname".inp", "r")) {
freopen(taskname".inp", "r", stdin);
freopen(taskname".out", "w", stdout);
}
cin.tie(0)->sync_with_stdio(0);
cin >> n >> m;
int N = sqrt(n);
for(int i = 0; i < m; i ++) {
int x, y;
cin >> x >> y;
adj[x + 1].push_back(y);
b[i] = x + 1;
}
for(int i = 1; i <= n; i ++) {
for(int j = 0; j <= N; j ++) {
f[i][j] = INF;
}
}
priority_queue<array<int, 3>, vector<array<int, 3>>, greater<array<int, 3>>> pq;
f[b[0]][0] = 0;
pq.push({0, b[0], 0});
while(!pq.empty()) {
int u = pq.top()[1];
int d = pq.top()[0];
int k = pq.top()[2];
pq.pop();
if(d > f[u][k]) continue ;
if(u == b[1]) {
cout << d << "\n";
return 0;
}
for(int p : adj[u]) {
if(p <= N) {
if(k) {
for(int i : {-1, 1}) {
int v = u + p * i;
if(v >= 1 && v <= n && f[v][p] > d + 1) {
f[v][p] = d + 1;
pq.push({f[v][p], v, p});
}
}
} else {
if(f[u][p] > d) {
f[u][p] = d;
pq.push({f[u][p], u, p});
}
}
} else {
for(int v = max(1, u % p); v <= n; v += p) {
if(f[v][0] > d + abs(u - v) / p) {
f[v][0] = d + abs(u - v) / p;
pq.push({f[v][0], v, 0});
}
}
}
}
if(k) {
for(int i : {-1, 1}) {
int v = u + k * i;
if(v >= 1 && v <= n && f[v][k] > d + 1) {
f[v][k] = d + 1;
pq.push({f[v][k], v, k});
}
}
}
}
cout << -1 << "\n";
return 0;
}
Compilation message
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:16:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
16 | freopen(taskname".inp", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:17:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
17 | freopen(taskname".out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
980 KB |
Output is correct |
2 |
Correct |
1 ms |
980 KB |
Output is correct |
3 |
Correct |
1 ms |
980 KB |
Output is correct |
4 |
Correct |
1 ms |
980 KB |
Output is correct |
5 |
Correct |
1 ms |
980 KB |
Output is correct |
6 |
Correct |
1 ms |
980 KB |
Output is correct |
7 |
Correct |
1 ms |
980 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
980 KB |
Output is correct |
2 |
Correct |
1 ms |
980 KB |
Output is correct |
3 |
Correct |
1 ms |
980 KB |
Output is correct |
4 |
Correct |
1 ms |
980 KB |
Output is correct |
5 |
Correct |
1 ms |
980 KB |
Output is correct |
6 |
Correct |
1 ms |
980 KB |
Output is correct |
7 |
Correct |
1 ms |
980 KB |
Output is correct |
8 |
Correct |
1 ms |
980 KB |
Output is correct |
9 |
Correct |
1 ms |
1044 KB |
Output is correct |
10 |
Correct |
1 ms |
1048 KB |
Output is correct |
11 |
Correct |
1 ms |
1108 KB |
Output is correct |
12 |
Correct |
1 ms |
1108 KB |
Output is correct |
13 |
Correct |
1 ms |
1108 KB |
Output is correct |
14 |
Incorrect |
1 ms |
1108 KB |
Output isn't correct |
15 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
980 KB |
Output is correct |
2 |
Correct |
1 ms |
980 KB |
Output is correct |
3 |
Correct |
1 ms |
980 KB |
Output is correct |
4 |
Correct |
1 ms |
980 KB |
Output is correct |
5 |
Correct |
1 ms |
980 KB |
Output is correct |
6 |
Correct |
1 ms |
980 KB |
Output is correct |
7 |
Correct |
1 ms |
980 KB |
Output is correct |
8 |
Correct |
1 ms |
980 KB |
Output is correct |
9 |
Correct |
1 ms |
1108 KB |
Output is correct |
10 |
Correct |
1 ms |
1112 KB |
Output is correct |
11 |
Correct |
1 ms |
1108 KB |
Output is correct |
12 |
Correct |
1 ms |
1108 KB |
Output is correct |
13 |
Correct |
1 ms |
1056 KB |
Output is correct |
14 |
Incorrect |
1 ms |
1108 KB |
Output isn't correct |
15 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
980 KB |
Output is correct |
2 |
Correct |
1 ms |
980 KB |
Output is correct |
3 |
Correct |
1 ms |
1048 KB |
Output is correct |
4 |
Correct |
1 ms |
980 KB |
Output is correct |
5 |
Correct |
1 ms |
980 KB |
Output is correct |
6 |
Correct |
1 ms |
980 KB |
Output is correct |
7 |
Correct |
1 ms |
980 KB |
Output is correct |
8 |
Correct |
1 ms |
980 KB |
Output is correct |
9 |
Correct |
1 ms |
980 KB |
Output is correct |
10 |
Correct |
1 ms |
1108 KB |
Output is correct |
11 |
Correct |
1 ms |
1108 KB |
Output is correct |
12 |
Correct |
1 ms |
1108 KB |
Output is correct |
13 |
Correct |
1 ms |
1052 KB |
Output is correct |
14 |
Incorrect |
1 ms |
1108 KB |
Output isn't correct |
15 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
980 KB |
Output is correct |
2 |
Correct |
1 ms |
980 KB |
Output is correct |
3 |
Correct |
1 ms |
980 KB |
Output is correct |
4 |
Correct |
1 ms |
980 KB |
Output is correct |
5 |
Correct |
1 ms |
980 KB |
Output is correct |
6 |
Correct |
1 ms |
980 KB |
Output is correct |
7 |
Correct |
1 ms |
980 KB |
Output is correct |
8 |
Correct |
1 ms |
980 KB |
Output is correct |
9 |
Correct |
1 ms |
980 KB |
Output is correct |
10 |
Correct |
1 ms |
1044 KB |
Output is correct |
11 |
Correct |
1 ms |
1052 KB |
Output is correct |
12 |
Correct |
1 ms |
1108 KB |
Output is correct |
13 |
Correct |
1 ms |
1056 KB |
Output is correct |
14 |
Incorrect |
1 ms |
1108 KB |
Output isn't correct |
15 |
Halted |
0 ms |
0 KB |
- |