Submission #499938

# Submission time Handle Problem Language Result Execution time Memory
499938 2021-12-30T05:40:40 Z zhougz Power Plant (JOI20_power) C++17
100 / 100
155 ms 28256 KB
#include <bits/stdc++.h>

using namespace std;

int n, res;
const int MAXN = 200'050;
vector<int> v[MAXN];
string s;
bool has_gen[MAXN];

int dfs(int x, int p) {
	int mx = 0, sum = 0;
	for (auto z : v[x]) {
		if (z != p) {
			int dp = dfs(z, x);
			mx = max(mx, dp);
			sum += dp;
		}
	}
	int ans;
	// My key concern was that if we assume there is
	// an ON node above x, but there actually isn't.
	// But in ans we can pretend x is the root node
	// E.g. if there is actually no ON node above x
	// then one possible case for ans would be
	// mx + 1 (ON x if has_gen[x]) (although dp is still 1)
	// Basically also calculate ans at each node assuming the root of the tree is x besides dp
	if (!has_gen[x]) {
		ans = sum;
		res = max(res, ans);
		return sum; // = dp
	}
	// Force generator ON
	ans = 1 + mx; // Assuming x is the root (i.e. no ON above x)
	int ret = 1; // Assuming has ON above x, we must pick only 1
	// Force generator OFF
	ans = max(ans, sum - 1); // Again assuming x is the root
	ret = max(ret, sum - 1); // Even if there is ON above x it's still this. Here we maximise dp before returning it
	res = max(res, ans);
	return ret;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> n;
	for (int i = 0, a, b; i < n - 1; i++) {
		cin >> a >> b;
		v[a].push_back(b);
		v[b].push_back(a);
	}
	cin >> s;
	for (int i = 1; i <= n; i++) {
		has_gen[i] = s[i - 1] == '1';
	}
	dfs(1, -1);
	cout << res;
	return 0;
}
# Verdict Execution time Memory Grader output
1 Correct 3 ms 4940 KB Output is correct
2 Correct 2 ms 4940 KB Output is correct
3 Correct 3 ms 4940 KB Output is correct
4 Correct 3 ms 4940 KB Output is correct
5 Correct 3 ms 5012 KB Output is correct
6 Correct 3 ms 4940 KB Output is correct
7 Correct 4 ms 5020 KB Output is correct
8 Correct 3 ms 4932 KB Output is correct
9 Correct 3 ms 4940 KB Output is correct
10 Correct 2 ms 4940 KB Output is correct
11 Correct 3 ms 5012 KB Output is correct
12 Correct 3 ms 4916 KB Output is correct
13 Correct 2 ms 4940 KB Output is correct
14 Correct 3 ms 4940 KB Output is correct
15 Correct 3 ms 5016 KB Output is correct
16 Correct 3 ms 4940 KB Output is correct
17 Correct 2 ms 4940 KB Output is correct
18 Correct 4 ms 4940 KB Output is correct
19 Correct 3 ms 4980 KB Output is correct
20 Correct 2 ms 4940 KB Output is correct
21 Correct 2 ms 5012 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 3 ms 4940 KB Output is correct
2 Correct 2 ms 4940 KB Output is correct
3 Correct 3 ms 4940 KB Output is correct
4 Correct 3 ms 4940 KB Output is correct
5 Correct 3 ms 5012 KB Output is correct
6 Correct 3 ms 4940 KB Output is correct
7 Correct 4 ms 5020 KB Output is correct
8 Correct 3 ms 4932 KB Output is correct
9 Correct 3 ms 4940 KB Output is correct
10 Correct 2 ms 4940 KB Output is correct
11 Correct 3 ms 5012 KB Output is correct
12 Correct 3 ms 4916 KB Output is correct
13 Correct 2 ms 4940 KB Output is correct
14 Correct 3 ms 4940 KB Output is correct
15 Correct 3 ms 5016 KB Output is correct
16 Correct 3 ms 4940 KB Output is correct
17 Correct 2 ms 4940 KB Output is correct
18 Correct 4 ms 4940 KB Output is correct
19 Correct 3 ms 4980 KB Output is correct
20 Correct 2 ms 4940 KB Output is correct
21 Correct 2 ms 5012 KB Output is correct
22 Correct 3 ms 5068 KB Output is correct
23 Correct 3 ms 5068 KB Output is correct
24 Correct 3 ms 5068 KB Output is correct
25 Correct 4 ms 5028 KB Output is correct
26 Correct 3 ms 5068 KB Output is correct
27 Correct 4 ms 5020 KB Output is correct
28 Correct 4 ms 5076 KB Output is correct
29 Correct 4 ms 5196 KB Output is correct
30 Correct 3 ms 5080 KB Output is correct
31 Correct 3 ms 5068 KB Output is correct
32 Correct 3 ms 5068 KB Output is correct
33 Correct 4 ms 5068 KB Output is correct
34 Correct 3 ms 5068 KB Output is correct
35 Correct 3 ms 5028 KB Output is correct
36 Correct 3 ms 5196 KB Output is correct
37 Correct 4 ms 5020 KB Output is correct
38 Correct 3 ms 5068 KB Output is correct
39 Correct 3 ms 5068 KB Output is correct
40 Correct 3 ms 5020 KB Output is correct
41 Correct 3 ms 5068 KB Output is correct
42 Correct 3 ms 5068 KB Output is correct
43 Correct 3 ms 5120 KB Output is correct
44 Correct 3 ms 5068 KB Output is correct
45 Correct 4 ms 5072 KB Output is correct
46 Correct 5 ms 5028 KB Output is correct
47 Correct 3 ms 5068 KB Output is correct
48 Correct 3 ms 5076 KB Output is correct
49 Correct 3 ms 5068 KB Output is correct
50 Correct 3 ms 5068 KB Output is correct
51 Correct 3 ms 5004 KB Output is correct
52 Correct 3 ms 5068 KB Output is correct
53 Correct 3 ms 5068 KB Output is correct
54 Correct 3 ms 5028 KB Output is correct
55 Correct 3 ms 5068 KB Output is correct
56 Correct 3 ms 5068 KB Output is correct
57 Correct 5 ms 5196 KB Output is correct
58 Correct 3 ms 5068 KB Output is correct
59 Correct 4 ms 5068 KB Output is correct
60 Correct 4 ms 5048 KB Output is correct
61 Correct 3 ms 5068 KB Output is correct
62 Correct 3 ms 5196 KB Output is correct
63 Correct 4 ms 5024 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 3 ms 4940 KB Output is correct
2 Correct 2 ms 4940 KB Output is correct
3 Correct 3 ms 4940 KB Output is correct
4 Correct 3 ms 4940 KB Output is correct
5 Correct 3 ms 5012 KB Output is correct
6 Correct 3 ms 4940 KB Output is correct
7 Correct 4 ms 5020 KB Output is correct
8 Correct 3 ms 4932 KB Output is correct
9 Correct 3 ms 4940 KB Output is correct
10 Correct 2 ms 4940 KB Output is correct
11 Correct 3 ms 5012 KB Output is correct
12 Correct 3 ms 4916 KB Output is correct
13 Correct 2 ms 4940 KB Output is correct
14 Correct 3 ms 4940 KB Output is correct
15 Correct 3 ms 5016 KB Output is correct
16 Correct 3 ms 4940 KB Output is correct
17 Correct 2 ms 4940 KB Output is correct
18 Correct 4 ms 4940 KB Output is correct
19 Correct 3 ms 4980 KB Output is correct
20 Correct 2 ms 4940 KB Output is correct
21 Correct 2 ms 5012 KB Output is correct
22 Correct 3 ms 5068 KB Output is correct
23 Correct 3 ms 5068 KB Output is correct
24 Correct 3 ms 5068 KB Output is correct
25 Correct 4 ms 5028 KB Output is correct
26 Correct 3 ms 5068 KB Output is correct
27 Correct 4 ms 5020 KB Output is correct
28 Correct 4 ms 5076 KB Output is correct
29 Correct 4 ms 5196 KB Output is correct
30 Correct 3 ms 5080 KB Output is correct
31 Correct 3 ms 5068 KB Output is correct
32 Correct 3 ms 5068 KB Output is correct
33 Correct 4 ms 5068 KB Output is correct
34 Correct 3 ms 5068 KB Output is correct
35 Correct 3 ms 5028 KB Output is correct
36 Correct 3 ms 5196 KB Output is correct
37 Correct 4 ms 5020 KB Output is correct
38 Correct 3 ms 5068 KB Output is correct
39 Correct 3 ms 5068 KB Output is correct
40 Correct 3 ms 5020 KB Output is correct
41 Correct 3 ms 5068 KB Output is correct
42 Correct 3 ms 5068 KB Output is correct
43 Correct 3 ms 5120 KB Output is correct
44 Correct 3 ms 5068 KB Output is correct
45 Correct 4 ms 5072 KB Output is correct
46 Correct 5 ms 5028 KB Output is correct
47 Correct 3 ms 5068 KB Output is correct
48 Correct 3 ms 5076 KB Output is correct
49 Correct 3 ms 5068 KB Output is correct
50 Correct 3 ms 5068 KB Output is correct
51 Correct 3 ms 5004 KB Output is correct
52 Correct 3 ms 5068 KB Output is correct
53 Correct 3 ms 5068 KB Output is correct
54 Correct 3 ms 5028 KB Output is correct
55 Correct 3 ms 5068 KB Output is correct
56 Correct 3 ms 5068 KB Output is correct
57 Correct 5 ms 5196 KB Output is correct
58 Correct 3 ms 5068 KB Output is correct
59 Correct 4 ms 5068 KB Output is correct
60 Correct 4 ms 5048 KB Output is correct
61 Correct 3 ms 5068 KB Output is correct
62 Correct 3 ms 5196 KB Output is correct
63 Correct 4 ms 5024 KB Output is correct
64 Correct 154 ms 14648 KB Output is correct
65 Correct 127 ms 14596 KB Output is correct
66 Correct 110 ms 14512 KB Output is correct
67 Correct 112 ms 14556 KB Output is correct
68 Correct 126 ms 14560 KB Output is correct
69 Correct 155 ms 14592 KB Output is correct
70 Correct 129 ms 14664 KB Output is correct
71 Correct 118 ms 14508 KB Output is correct
72 Correct 111 ms 14592 KB Output is correct
73 Correct 141 ms 27136 KB Output is correct
74 Correct 131 ms 27168 KB Output is correct
75 Correct 128 ms 14456 KB Output is correct
76 Correct 103 ms 14476 KB Output is correct
77 Correct 116 ms 14424 KB Output is correct
78 Correct 111 ms 14468 KB Output is correct
79 Correct 117 ms 14476 KB Output is correct
80 Correct 107 ms 14492 KB Output is correct
81 Correct 94 ms 14864 KB Output is correct
82 Correct 101 ms 14620 KB Output is correct
83 Correct 116 ms 19612 KB Output is correct
84 Correct 128 ms 21756 KB Output is correct
85 Correct 117 ms 21488 KB Output is correct
86 Correct 123 ms 15952 KB Output is correct
87 Correct 117 ms 15400 KB Output is correct
88 Correct 104 ms 15808 KB Output is correct
89 Correct 122 ms 15848 KB Output is correct
90 Correct 120 ms 15552 KB Output is correct
91 Correct 133 ms 15792 KB Output is correct
92 Correct 102 ms 16196 KB Output is correct
93 Correct 109 ms 18512 KB Output is correct
94 Correct 102 ms 20292 KB Output is correct
95 Correct 94 ms 18980 KB Output is correct
96 Correct 120 ms 17208 KB Output is correct
97 Correct 130 ms 15640 KB Output is correct
98 Correct 101 ms 15128 KB Output is correct
99 Correct 123 ms 14868 KB Output is correct
100 Correct 107 ms 18056 KB Output is correct
101 Correct 120 ms 16000 KB Output is correct
102 Correct 123 ms 15276 KB Output is correct
103 Correct 125 ms 15140 KB Output is correct
104 Correct 63 ms 15356 KB Output is correct
105 Correct 130 ms 23980 KB Output is correct
106 Correct 71 ms 15268 KB Output is correct
107 Correct 73 ms 15360 KB Output is correct
108 Correct 135 ms 27876 KB Output is correct
109 Correct 64 ms 15412 KB Output is correct
110 Correct 147 ms 28256 KB Output is correct
111 Correct 115 ms 14480 KB Output is correct