///
/// ♪ Pizza mozzarella rella rella rella... ♪
///
#define _USE_MATH_DEFINES
#define FAST ios::sync_with_stdio(false),cin.tie(0);
#include <bits/stdc++.h>
#define Loop(x, l, r) for(int x = (l); x < (r); ++x)
#define LoopR(x, l, r) for(int x = (r)-1; x >= (l); --x)
#define all(x) x.begin(), x.end()
#define Kill(x) exit((cout << (x) << '\n', 0))
#define YN(flag) ((flag)? "YES": "NO")
#define F first
#define S second
typedef long long ll;
typedef unsigned long long ull;
typedef std::pair<int,int> pii;
typedef std::pair<ll ,ll > pll;
using namespace std;
const int N = 30'010;
const int mod = 20000003;
struct mymap
{
vector<pii> v[mod];
int count(int x)
{
int y = x%mod;
for(auto& [a, b] : v[y])
if(a==x)
return 1;
return 0;
}
int& operator[](int x)
{
int y = x%mod;
for(auto& [a, b] : v[y])
if(a==x)
return b;
v[y].emplace_back(x,0);
return v[y].back().S;
}
};
mymap d;
vector<int> P[N];
bool vis[N];
int n, m;
void bfs(int sv, int sp)
{
vector<int> q;
vis[sv] = 1;
for(auto p : P[sv]) if(!d.count(sv<<15^p)) d[sv<<15^p] = 0, q.push_back(sv<<15^p);
if(!d.count(sv<<15^sp)) d[sv<<15^sp] = 0, q.push_back(sv<<15^sp);
for(int i = 0, j = q.size(), d = 0; i < q.size(); j = q.size(), ++d) for(; i < j; ++i)
{
if(q.size() > 8'000'000) exit(0);
int v = q[i]>>15, p = q[i]&32767;
//cerr << v << ' ' << p << ": " << d << '\n';
int u = v+p;
if(0 <= u && u < n)
{
if(!vis[u]){
vis[u] = 1;
for(auto p : P[u]) if(!::d.count(u<<15^p)) ::d[u<<15^p] = d+1, q.push_back(u<<15^p);
}
if(!::d.count(u<<15^p)) ::d[u<<15^p] = d+1, q.push_back(u<<15^p);
}
u = v-p;
if(0 <= u && u < n)
{
if(!vis[u]){
vis[u] = 1;
for(auto p : P[u]) if(!::d.count(u<<15^p)) ::d[u<<15^p] = d+1, q.push_back(u<<15^p);
}
if(!::d.count(u<<15^p)) ::d[u<<15^p] = d+1, q.push_back(u<<15^p);
}
}
}
bool isPrime(int n)
{
for(int d = 2; d*d <= n; ++d)
if(n%d == 0)
return 0;
return 1;
}
int main()
{
//Loop(i,20000000,INT_MAX) if(isPrime(i)){cout << i;break;}
FAST;
cin >> n >> m;
int p, src, des, dmy;
cin >> src >> p;
cin >> des >> dmy;
P[des].push_back(dmy);
Loop(i,2,m)
{
int v, p;
cin >> v >> p;
P[v].push_back(p);
}
bfs(src, p);
cout << (d.count(des<<15^dmy)? d[des<<15^dmy]: -1) << '\n';
}
Compilation message
skyscraper.cpp: In function 'void bfs(int, int)':
skyscraper.cpp:57:43: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
57 | for(int i = 0, j = q.size(), d = 0; i < q.size(); j = q.size(), ++d) for(; i < j; ++i)
| ~~^~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
117 ms |
262148 KB |
Execution killed with signal 9 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
122 ms |
262148 KB |
Execution killed with signal 9 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
123 ms |
262148 KB |
Execution killed with signal 9 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
121 ms |
262148 KB |
Execution killed with signal 9 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
118 ms |
262148 KB |
Execution killed with signal 9 |
2 |
Halted |
0 ms |
0 KB |
- |