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Submission #633777

# Submission time Handle Problem Language Result Execution time Memory
633777 2022-08-23T08:35:45 Z NothingXD LOSTIKS (INOI20_lostiks) C++17
59 / 100
 2000 ms 196312 KB 
#include<bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
//typedef __uint128_t L;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
	cerr << " " << H;
	debug_out(T...);
}

#define debug(...) cerr << "(" << #__VA_ARGS__ << "):", debug_out(__VA_ARGS__)
#define all(x) x.begin(), x.end()
#define MP(x, y) make_pair(x, y)
#define F first
#define S second

const int maxn = 1e6 + 10;
const int maxm = 20;
const int mask = (1 << 20);
const int inf = 1e9;

int n, m, S, T, edge[maxm][3], comp[maxn], cnt, sz, par[mask][maxm+1], h[maxm+1][maxn], dp[mask][maxm+1];
vector<int> g[maxn];
bool vis[maxn];

int first[maxn], to[maxn << 1], nxt[maxn << 1], ecnt;

void add(int u, int v){
	nxt[++ecnt] = first[u];
	to[ecnt] = v;
	first[u] = ecnt;
}

void dfs(int v, int *h, int p = -1){
	for (int i = first[v]; i; i = nxt[i]){
		int u = to[i];
		if (u != p){
			h[u] = h[v] + 1;
			dfs(u, h, v);
		}
	}
}

void getcomp(int v, int p = -1){
	vis[v] = true;
	comp[v] = cnt;
	for (auto u: g[v]) if (u != p) getcomp(u, v);
}

int getpar(int *par, int v){
	//debug(v, par[v]);
	return (par[v] < 0? v: par[v] = getpar(par, par[v]));
}

void merge(int *par, int u, int v){
	if ((u = getpar(par, u)) == (v = getpar(par, v))) return;
	if (par[u] > par[v]) swap(u, v);
	par[u] += par[v];
	par[v] = u;
}

int main(){
//	ios_base::sync_with_stdio(false); cin.tie(0);

	scanf("%d%d%d", &n, &S, &T);
	for (int i = 1; i < n; i++){
		int u, v, w; scanf("%d%d%d", &u, &v, &w);
		add(u, v);
		add(v, u);
		if (w == 0){
			g[u].push_back(v);
			g[v].push_back(u);
		}
		else{
			edge[m][0] = u;
			edge[m][1] = v;
			edge[m][2] = w;
			m++;
		}
	}

	dfs(S, h[m]);

	for (int i = 0; i < m; i++){
		if (h[m][edge[i][0]] > h[m][edge[i][1]]) swap(edge[i][0], edge[i][1]);
		dfs(edge[i][0], h[i]);
	}

	assert(m <= 20);

	for (int i = 1; i <= n; i++){
		if (!vis[i]){
			getcomp(i);
			cnt++;
		}
	}

	for (int i = (1 << m) - 1; ~i; i--){
		if (i == (1 << m) - 1){
			for (int j = 0; j <= m; j++) par[i][j] = -1;
			continue;
		}
		int tmp = __builtin_ctz(((1 << m) - 1) ^ i);
		for (int j = 0; j <= m; j++){
			par[i][j] = par[i^(1 << tmp)][j];
		}
		merge(par[i], comp[edge[tmp][0]], comp[edge[tmp][1]]);
	}

	for (int i = 0; i <= m; i++){
		dp[0][i] = h[i][T];
	}

	for (int msk = 1; msk < (1 << m); msk++){
		for (int i = 0; i <= m; i++){
			int v = (i == m? S: edge[i][0]);
			dp[msk][i] = inf;
			if (getpar(par[msk], comp[T]) == getpar(par[msk], comp[v])){
				dp[msk][i] = h[i][T];
				continue;
			}
			for (int tmp = msk; tmp; tmp ^= tmp & -tmp){
				int j = __builtin_ctz(tmp);
				if (getpar(par[msk], comp[edge[j][2]]) == getpar(par[msk], comp[v]) &&
					   	getpar(par[msk], comp[edge[j][0]]) == getpar(par[msk], comp[v])){
					dp[msk][i] = min(dp[msk][i], dp[msk^(1 << j)][j] + h[i][edge[j][2]] + h[j][edge[j][2]]);
				}
			}
		}
	}

	if (dp[(1 << m) - 1][m] == inf) printf("%d\n", -1);
	else printf("%d\n", dp[(1 << m) - 1][m]);


	return 0;
}

Compilation message

Main.cpp: In function 'int main()':
Main.cpp:73:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |  scanf("%d%d%d", &n, &S, &T);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:75:21: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |   int u, v, w; scanf("%d%d%d", &u, &v, &w);
      |                ~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 13 ms 23764 KB Output is correct
3 Correct 93 ms 32816 KB Output is correct
4 Correct 79 ms 32884 KB Output is correct
5 Correct 87 ms 32932 KB Output is correct
6 Correct 79 ms 32792 KB Output is correct
7 Correct 80 ms 32880 KB Output is correct
8 Correct 89 ms 32872 KB Output is correct
9 Correct 79 ms 33232 KB Output is correct
10 Correct 79 ms 32972 KB Output is correct
11 Correct 78 ms 32940 KB Output is correct
12 Correct 70 ms 34800 KB Output is correct
13 Correct 71 ms 35152 KB Output is correct
14 Correct 76 ms 34844 KB Output is correct
15 Correct 74 ms 35044 KB Output is correct
16 Correct 71 ms 35636 KB Output is correct
17 Correct 71 ms 35792 KB Output is correct
18 Correct 71 ms 36156 KB Output is correct
19 Correct 80 ms 40252 KB Output is correct
20 Correct 97 ms 40100 KB Output is correct
21 Correct 91 ms 39964 KB Output is correct
22 Correct 13 ms 23896 KB Output is correct
23 Correct 13 ms 23848 KB Output is correct
24 Correct 14 ms 23892 KB Output is correct
25 Correct 13 ms 23892 KB Output is correct
26 Correct 13 ms 23892 KB Output is correct

Subtask #2
36.0 / 36.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 12 ms 23764 KB Output is correct
3 Correct 14 ms 24108 KB Output is correct
4 Correct 14 ms 24020 KB Output is correct
5 Correct 1142 ms 111040 KB Output is correct
6 Correct 1126 ms 111296 KB Output is correct
7 Correct 1161 ms 111220 KB Output is correct
8 Correct 1111 ms 111112 KB Output is correct
9 Correct 1183 ms 111120 KB Output is correct
10 Correct 1022 ms 111296 KB Output is correct
11 Correct 982 ms 111120 KB Output is correct
12 Correct 984 ms 111188 KB Output is correct
13 Correct 925 ms 111108 KB Output is correct
14 Correct 996 ms 111024 KB Output is correct
15 Correct 1241 ms 111132 KB Output is correct
16 Correct 972 ms 111204 KB Output is correct
17 Correct 1164 ms 111200 KB Output is correct
18 Correct 1047 ms 111264 KB Output is correct
19 Correct 948 ms 111344 KB Output is correct
20 Correct 999 ms 111432 KB Output is correct
21 Correct 967 ms 111340 KB Output is correct
22 Correct 1039 ms 111684 KB Output is correct
23 Correct 958 ms 111644 KB Output is correct
24 Correct 948 ms 111576 KB Output is correct
25 Correct 1000 ms 196312 KB Output is correct

Subtask #3
0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 13 ms 23764 KB Output is correct
3 Correct 93 ms 32816 KB Output is correct
4 Correct 79 ms 32884 KB Output is correct
5 Correct 87 ms 32932 KB Output is correct
6 Correct 79 ms 32792 KB Output is correct
7 Correct 80 ms 32880 KB Output is correct
8 Correct 89 ms 32872 KB Output is correct
9 Correct 79 ms 33232 KB Output is correct
10 Correct 79 ms 32972 KB Output is correct
11 Correct 78 ms 32940 KB Output is correct
12 Correct 70 ms 34800 KB Output is correct
13 Correct 71 ms 35152 KB Output is correct
14 Correct 76 ms 34844 KB Output is correct
15 Correct 74 ms 35044 KB Output is correct
16 Correct 71 ms 35636 KB Output is correct
17 Correct 71 ms 35792 KB Output is correct
18 Correct 71 ms 36156 KB Output is correct
19 Correct 80 ms 40252 KB Output is correct
20 Correct 97 ms 40100 KB Output is correct
21 Correct 91 ms 39964 KB Output is correct
22 Correct 13 ms 23896 KB Output is correct
23 Correct 13 ms 23848 KB Output is correct
24 Correct 14 ms 23892 KB Output is correct
25 Correct 13 ms 23892 KB Output is correct
26 Correct 13 ms 23892 KB Output is correct
27 Correct 12 ms 23764 KB Output is correct
28 Correct 12 ms 23764 KB Output is correct
29 Correct 14 ms 24108 KB Output is correct
30 Correct 14 ms 24020 KB Output is correct
31 Correct 1142 ms 111040 KB Output is correct
32 Correct 1126 ms 111296 KB Output is correct
33 Correct 1161 ms 111220 KB Output is correct
34 Correct 1111 ms 111112 KB Output is correct
35 Correct 1183 ms 111120 KB Output is correct
36 Correct 1022 ms 111296 KB Output is correct
37 Correct 982 ms 111120 KB Output is correct
38 Correct 984 ms 111188 KB Output is correct
39 Correct 925 ms 111108 KB Output is correct
40 Correct 996 ms 111024 KB Output is correct
41 Correct 1241 ms 111132 KB Output is correct
42 Correct 972 ms 111204 KB Output is correct
43 Correct 1164 ms 111200 KB Output is correct
44 Correct 1047 ms 111264 KB Output is correct
45 Correct 948 ms 111344 KB Output is correct
46 Correct 999 ms 111432 KB Output is correct
47 Correct 967 ms 111340 KB Output is correct
48 Correct 1039 ms 111684 KB Output is correct
49 Correct 958 ms 111644 KB Output is correct
50 Correct 948 ms 111576 KB Output is correct
51 Correct 1000 ms 196312 KB Output is correct
52 Execution timed out 2079 ms 121640 KB Time limit exceeded
53 Halted 0 ms 0 KB -