# |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
440035 |
2021-07-01T13:30:23 Z |
dutch |
Islands (IOI08_islands) |
C++17 |
|
1187 ms |
131076 KB |
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define w (a[e][1])
#define V() (e == u ? a[e][0] : e)
#define v V()
const int LIM = 1e6;
vector<int> g[LIM];
array<int, 2> a[LIM];
int r, p[LIM];
ll b[LIM], d[LIM], s[LIM], best;
bitset<LIM> vis;
void dfs(int u){
vis[u] = 1, s[u] = d[u];
ll curr = 0;
for(int e : g[u]) if(e != r && !vis[v]){
p[v] = u;
d[v] = d[u] + (ll)w;
dfs(v);
s[u] = max(s[u], s[v]);
best = max(best, curr + s[v] - d[u]);
curr = max(curr, s[v] - d[u]);
}
}
void findCycle(int u, int par){
vis[u] = 1;
for(int e : g[u]) if(e != par){
if(vis[v]) return void(r = e + (vis[u] = 0));
findCycle(v, e);
if(r >= 0) break;
}
vis[u] = 0;
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
int n; cin >> n;
for(int i=0; i<n; ++i){
cin >> a[i][0] >> a[i][1]; --a[i][0];
g[a[i][0]].push_back(i);
g[i].push_back(i);
}
fill(p, p+n, -1);
ll ans = 0;
for(int z=0; z<n; ++z){
if(vis[z]) continue;
r = -1, best = 0;
findCycle(z, -1);
assert(r >= 0);
dfs(r);
function<void(int, int)> find = [&](int u, int last){
b[u] = d[u];
for(int e : g[u])
if(e != r && v != p[u] && v != last) b[u] = max(b[u], s[v]);
if(u != r){
find(p[u], u);
b[u] = max(b[u], b[p[u]]);
}
};
find(a[r][0], -1);
int u = a[r][0], last = -1;
ll res = 0;
while(u != r){
ll mx = 0, ex = 0;
for(int e : g[u])
if(e != r && v != p[u] && v != last) mx = max(mx, s[v] - d[u]);
res = max(res, d[a[r][0]] - d[u] + mx + b[p[u]]);
last = u;
u = p[u];
}
res += a[r][1];
// cout << r+1 << ' ' << best << ' ' << res << '\n';
ans += max(best, res);
}
cout << ans;
}
Compilation message
islands.cpp: In function 'int main()':
islands.cpp:75:15: warning: unused variable 'ex' [-Wunused-variable]
75 | ll mx = 0, ex = 0;
| ^~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
14 ms |
23756 KB |
Output is correct |
2 |
Correct |
15 ms |
23836 KB |
Output is correct |
3 |
Correct |
17 ms |
23884 KB |
Output is correct |
4 |
Correct |
15 ms |
23836 KB |
Output is correct |
5 |
Correct |
16 ms |
23812 KB |
Output is correct |
6 |
Correct |
14 ms |
23756 KB |
Output is correct |
7 |
Correct |
16 ms |
23716 KB |
Output is correct |
8 |
Correct |
15 ms |
23756 KB |
Output is correct |
9 |
Correct |
15 ms |
23844 KB |
Output is correct |
10 |
Correct |
15 ms |
23852 KB |
Output is correct |
11 |
Correct |
15 ms |
23768 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
21 ms |
23836 KB |
Output is correct |
2 |
Correct |
17 ms |
23932 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
19 ms |
23884 KB |
Output is correct |
2 |
Correct |
20 ms |
24140 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
24 ms |
25024 KB |
Output is correct |
2 |
Correct |
33 ms |
27336 KB |
Output is correct |
3 |
Correct |
28 ms |
25224 KB |
Output is correct |
4 |
Correct |
20 ms |
24524 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
45 ms |
28664 KB |
Output is correct |
2 |
Correct |
63 ms |
31836 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
119 ms |
38804 KB |
Output is correct |
2 |
Correct |
112 ms |
44404 KB |
Output is correct |
3 |
Correct |
158 ms |
52216 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
170 ms |
51772 KB |
Output is correct |
2 |
Correct |
235 ms |
72744 KB |
Output is correct |
3 |
Correct |
282 ms |
83664 KB |
Output is correct |
4 |
Correct |
362 ms |
96576 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
347 ms |
86504 KB |
Output is correct |
2 |
Correct |
987 ms |
131072 KB |
Output is correct |
3 |
Correct |
333 ms |
78552 KB |
Output is correct |
4 |
Correct |
428 ms |
114340 KB |
Output is correct |
5 |
Correct |
416 ms |
113984 KB |
Output is correct |
6 |
Correct |
1187 ms |
82936 KB |
Output is correct |
7 |
Runtime error |
440 ms |
131076 KB |
Execution killed with signal 9 |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
392 ms |
131076 KB |
Execution killed with signal 9 |
2 |
Halted |
0 ms |
0 KB |
- |