| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 253926 | ChrisT | Jakarta Skyscrapers (APIO15_skyscraper) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<bits/stdc++.h>
#define hsh(x,y) (x)<<15|(y)
using namespace std;
const int MN = 30005;
int b[MN], p[MN];
pair<int,int> dq[11000000];
bitset<1000000000> vis;
vector<int> st[MN];
int main () {
int n,m;
scanf ("%d %d",&n,&m);
for (int i = 0; i < m; i++) {
scanf ("%d %d",&b[i],&p[i]);
st[b[i]].push_back(i);
}
int l = n, r = l + 1;
dq[l] = {hsh(b[0],p[0]),0};
while (l < r) {
int cur = dq[l].first>>15, power = dq[l].first & 0x7FFF, dist = dq[l].second; ++l;
if (cur == b[1]) return !printf ("%d\n",dist);
for (int i : st[cur]) if (!vis[hsh(cur,p[i])]) {
vis[hsh(cur,p[i])] = 1;
dq[--l] = {hsh(cur,p[i]),dist};
}
st[cur].clear();
if (cur >= power && !vis[hsh(cur-power,power)]) {
vis[hsh(cur-power,power)] = 1;
dq[r++] = {hsh(cur-power,power),dist+1};
}
if (cur + power < n && !vis[hsh(cur+power,power)]) {
vis[hsh(cur+power,power)] = 1;
dq[r++] = {hsh(cur+power,power),dist+1};
}
}
printf ("-1\n");
return 0;
}