| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 699696 |
2023-02-17T19:41:46 Z |
finn__ |
Pipes (BOI13_pipes) |
C++17 |
|
101 ms |
28232 KB |
#include <bits/stdc++.h>
using namespace std;
#define N 100000
#define M 500000
vector<pair<unsigned, unsigned>> g[N];
int64_t y[N], ans[M];
bitset<N> visited;
int64_t solve_for_tree(unsigned u, unsigned p1 = -1, unsigned p2 = -1)
{
int64_t val = 0;
for (auto const &[v, i] : g[u])
if (v != p1 && v != p2)
{
int64_t z = solve_for_tree(v, u);
ans[i] = y[v] - z;
val += ans[i];
}
return val;
}
unsigned find_cycle(unsigned u, vector<unsigned> &cycle, unsigned p = -1)
{
if (visited[u])
return u;
visited[u] = 1;
for (auto const &[v, i] : g[u])
if (v != p)
{
unsigned x = find_cycle(v, cycle, u);
if (x != UINT_MAX)
{
cycle.push_back(u);
return x == u ? UINT_MAX : x;
}
}
return UINT_MAX;
}
int main()
{
size_t n, m;
scanf("%zu %zu", &n, &m);
if (m > n)
{
printf("0\n");
return 0;
}
for (size_t i = 0; i < n; i++)
scanf("%" PRId64, y + i);
for (size_t i = 0; i < m; i++)
{
unsigned u, v;
scanf("%u %u", &u, &v);
g[u - 1].emplace_back(v - 1, i);
g[v - 1].emplace_back(u - 1, i);
}
if (m + 1 == n)
solve_for_tree(0);
else
{
vector<unsigned> cycle;
find_cycle(0, cycle);
vector<int64_t> ny(cycle.size());
for (size_t i = 0; i < cycle.size(); i++)
ny[i] = y[cycle[i]] - solve_for_tree(cycle[i], cycle[(i + 1) % cycle.size()], cycle[(i - 1 + cycle.size()) % cycle.size()]);
unsigned k;
for (auto const &[v, i] : g[cycle[0]])
if (v == cycle[1])
{
k = i;
break;
}
g[cycle[0]].erase(find(g[cycle[0]].begin(), g[cycle[0]].end(), make_pair(cycle[1], k)));
g[cycle[1]].erase(find(g[cycle[1]].begin(), g[cycle[1]].end(), make_pair(cycle[0], k)));
for (size_t z = 0; z < 2; z++)
{
ans[k] = 0;
for (size_t i = 0; i < cycle.size(); i++)
ans[k] += ny[(i + z) % cycle.size()] * ((i & 1) ? -1 : 1);
assert(!(ans[k] & 3));
ans[k] >>= 1;
y[cycle[0]] -= ans[k];
y[cycle[1]] -= ans[k];
if (!solve_for_tree(0))
break;
y[cycle[0]] += ans[k];
y[cycle[1]] += ans[k];
}
}
for (size_t i = 0; i < m; i++)
printf("%" PRId64 "\n", 2 * ans[i]);
}
Compilation message
pipes.cpp: In function 'int main()':
pipes.cpp:47:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
47 | scanf("%zu %zu", &n, &m);
| ~~~~~^~~~~~~~~~~~~~~~~~~
pipes.cpp:56:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
56 | scanf("%" PRId64, y + i);
| ~~~~~^~~~~~~~~~~~~~~~~~~
pipes.cpp:60:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
60 | scanf("%u %u", &u, &v);
| ~~~~~^~~~~~~~~~~~~~~~~
pipes.cpp:75:18: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
75 | unsigned k;
| ^
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 2 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 3 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 4 |
Correct |
54 ms |
8352 KB |
Output is correct |
| 5 |
Correct |
1 ms |
2660 KB |
Output is correct |
| 6 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 7 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 8 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 9 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 10 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 11 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 12 |
Correct |
2 ms |
2660 KB |
Output is correct |
| 13 |
Correct |
46 ms |
7160 KB |
Output is correct |
| 14 |
Correct |
49 ms |
8004 KB |
Output is correct |
| 15 |
Correct |
53 ms |
8396 KB |
Output is correct |
| 16 |
Correct |
44 ms |
7500 KB |
Output is correct |
| 17 |
Correct |
53 ms |
8336 KB |
Output is correct |
| 18 |
Correct |
54 ms |
8396 KB |
Output is correct |
| 19 |
Correct |
67 ms |
11008 KB |
Output is correct |
| 20 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 21 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 22 |
Correct |
54 ms |
8288 KB |
Output is correct |
| 23 |
Correct |
41 ms |
7084 KB |
Output is correct |
| 24 |
Correct |
53 ms |
8332 KB |
Output is correct |
| 25 |
Correct |
44 ms |
7348 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
3 ms |
5204 KB |
Execution killed with signal 6 |
| 2 |
Correct |
2 ms |
2772 KB |
Output is correct |
| 3 |
Incorrect |
78 ms |
10772 KB |
Output isn't correct |
| 4 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 5 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 6 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 7 |
Runtime error |
4 ms |
5204 KB |
Execution killed with signal 6 |
| 8 |
Runtime error |
4 ms |
5204 KB |
Execution killed with signal 6 |
| 9 |
Incorrect |
2 ms |
2644 KB |
Output isn't correct |
| 10 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 11 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 12 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 13 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 14 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 15 |
Correct |
2 ms |
2772 KB |
Output is correct |
| 16 |
Runtime error |
4 ms |
5332 KB |
Execution killed with signal 6 |
| 17 |
Incorrect |
2 ms |
2644 KB |
Output isn't correct |
| 18 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 19 |
Correct |
1 ms |
2648 KB |
Output is correct |
| 20 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 21 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 22 |
Runtime error |
5 ms |
5460 KB |
Execution killed with signal 6 |
| 23 |
Runtime error |
47 ms |
21420 KB |
Execution killed with signal 6 |
| 24 |
Runtime error |
67 ms |
23516 KB |
Execution killed with signal 6 |
| 25 |
Incorrect |
74 ms |
10792 KB |
Output isn't correct |
| 26 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 27 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 28 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 29 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 30 |
Correct |
84 ms |
13392 KB |
Output is correct |
| 31 |
Runtime error |
64 ms |
28232 KB |
Execution killed with signal 6 |
| 32 |
Runtime error |
55 ms |
18492 KB |
Execution killed with signal 6 |
| 33 |
Incorrect |
76 ms |
11820 KB |
Output isn't correct |
| 34 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 35 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 36 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 37 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 38 |
Runtime error |
62 ms |
22192 KB |
Execution killed with signal 6 |
| 39 |
Runtime error |
57 ms |
17488 KB |
Execution killed with signal 6 |
| 40 |
Runtime error |
66 ms |
22920 KB |
Execution killed with signal 6 |
| 41 |
Incorrect |
101 ms |
14152 KB |
Output isn't correct |
| 42 |
Correct |
1 ms |
2648 KB |
Output is correct |
| 43 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 44 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 45 |
Correct |
1 ms |
2644 KB |
Output is correct |
| 46 |
Runtime error |
78 ms |
28076 KB |
Execution killed with signal 6 |
| 47 |
Runtime error |
74 ms |
23060 KB |
Execution killed with signal 6 |
| 48 |
Runtime error |
64 ms |
27844 KB |
Execution killed with signal 6 |
| 49 |
Incorrect |
66 ms |
8992 KB |
Output isn't correct |
| 50 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 51 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 52 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 53 |
Correct |
2 ms |
2644 KB |
Output is correct |
| 54 |
Runtime error |
65 ms |
24544 KB |
Execution killed with signal 6 |
