#include <bits/stdc++.h>
using namespace std;
#define int long long
#define iii tuple<int, int, int>
const int N = 50007;
const int block = 316;
int n, m, b[N], v[N], pw[N], dp[N][block + 7], ans = -1;
priority_queue<iii, vector<iii>, greater<iii>> pq;
int32_t main (){
ios::sync_with_stdio(false); cin.tie(nullptr);
if (fopen("test.inp", "r")){
freopen("test.inp", "r", stdin);
freopen("test.out", "w", stdout);
}
cin >> n >> m;
for (int i = 0; i < n; ++i)
for (int j = 0; j <= block + 1; ++j)
dp[i][j] = -1;
for (int i = 1; i <= m; ++i){
cin >> b[i] >> v[i];
pw[b[i]] = v[i];
if (i == 1)
pq.push({0, b[i], v[i]});
}
while (pq.size()){
auto P = pq.top(); pq.pop();
int D = get<0>(P);
int u = get<1>(P);
int t = get<2>(P); t = min(t, block + 1);
if (dp[u][t] != -1)
continue;
dp[u][t] = D;
if (u == b[2])
ans = min((ans == -1 ? (int)1e16 : ans), D);
if (t <= block){
if (u - t >= 0 && dp[u - t][t] == -1)
pq.push(make_tuple(D + 1, u - t, t));
if (u + t < n && dp[u + t][t] == -1)
pq.push(make_tuple(D + 1, u + t, t));
}
int X = pw[u];
if (X <= block){
if (u - X >= 0 && dp[u - X][X] == -1)
pq.push(make_tuple(D + 1, u - X, X));
if (u + X < n && dp[u + X][X] == -1)
pq.push(make_tuple(D + 1, u + X, X));
} else {
for (int i = u - X; i >= 0; i -= X)
if (dp[i][block + 1] == -1)
pq.push(make_tuple(D + (u - i) / X, i, X));
for (int i = u + X; i < n; i += X)
if (dp[i][block + 1] == -1)
pq.push(make_tuple(D + (i - u) / X, i, X));
}
}
cout << ans << "\n";
}
Compilation message
skyscraper.cpp: In function 'int32_t 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("test.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("test.out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2384 KB |
Output is correct |
2 |
Correct |
1 ms |
2384 KB |
Output is correct |
3 |
Correct |
1 ms |
2384 KB |
Output is correct |
4 |
Correct |
1 ms |
2384 KB |
Output is correct |
5 |
Correct |
1 ms |
2384 KB |
Output is correct |
6 |
Correct |
1 ms |
2384 KB |
Output is correct |
7 |
Correct |
1 ms |
2384 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2396 KB |
Output is correct |
2 |
Correct |
1 ms |
2384 KB |
Output is correct |
3 |
Correct |
1 ms |
2384 KB |
Output is correct |
4 |
Correct |
1 ms |
2384 KB |
Output is correct |
5 |
Correct |
1 ms |
2384 KB |
Output is correct |
6 |
Correct |
1 ms |
2384 KB |
Output is correct |
7 |
Correct |
1 ms |
2552 KB |
Output is correct |
8 |
Correct |
1 ms |
2384 KB |
Output is correct |
9 |
Correct |
1 ms |
2640 KB |
Output is correct |
10 |
Correct |
2 ms |
4688 KB |
Output is correct |
11 |
Incorrect |
2 ms |
4688 KB |
Output isn't correct |
12 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2384 KB |
Output is correct |
2 |
Correct |
1 ms |
2384 KB |
Output is correct |
3 |
Correct |
2 ms |
2384 KB |
Output is correct |
4 |
Correct |
1 ms |
2384 KB |
Output is correct |
5 |
Correct |
1 ms |
2556 KB |
Output is correct |
6 |
Correct |
1 ms |
2384 KB |
Output is correct |
7 |
Correct |
1 ms |
2384 KB |
Output is correct |
8 |
Correct |
1 ms |
2384 KB |
Output is correct |
9 |
Correct |
1 ms |
2640 KB |
Output is correct |
10 |
Correct |
2 ms |
4688 KB |
Output is correct |
11 |
Incorrect |
2 ms |
4688 KB |
Output isn't correct |
12 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2384 KB |
Output is correct |
2 |
Correct |
1 ms |
2384 KB |
Output is correct |
3 |
Correct |
1 ms |
2384 KB |
Output is correct |
4 |
Correct |
1 ms |
2384 KB |
Output is correct |
5 |
Correct |
1 ms |
2384 KB |
Output is correct |
6 |
Correct |
1 ms |
2384 KB |
Output is correct |
7 |
Correct |
1 ms |
2384 KB |
Output is correct |
8 |
Correct |
1 ms |
2384 KB |
Output is correct |
9 |
Correct |
2 ms |
2640 KB |
Output is correct |
10 |
Correct |
1 ms |
4688 KB |
Output is correct |
11 |
Incorrect |
1 ms |
4688 KB |
Output isn't correct |
12 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2384 KB |
Output is correct |
2 |
Correct |
1 ms |
2384 KB |
Output is correct |
3 |
Correct |
1 ms |
2384 KB |
Output is correct |
4 |
Correct |
1 ms |
2384 KB |
Output is correct |
5 |
Correct |
1 ms |
2384 KB |
Output is correct |
6 |
Correct |
1 ms |
2384 KB |
Output is correct |
7 |
Correct |
1 ms |
2384 KB |
Output is correct |
8 |
Correct |
1 ms |
2384 KB |
Output is correct |
9 |
Correct |
1 ms |
2812 KB |
Output is correct |
10 |
Correct |
1 ms |
4688 KB |
Output is correct |
11 |
Incorrect |
2 ms |
4688 KB |
Output isn't correct |
12 |
Halted |
0 ms |
0 KB |
- |