Submission #217722

# Submission time Handle Problem Language Result Execution time Memory
217722 2020-03-30T13:59:47 Z Fischer Valley (BOI19_valley) C++14
100 / 100
286 ms 36440 KB
#include <bits/stdc++.h>
#define re(x, y, z) for (int x=y; x<z; ++x)
#define trav(v, x) for (int v : x)
#define eb emplace_back
using namespace std;
const int maxn = 1e5 + 10;
long long h[maxn];
int lo[maxn], hi[maxn];
long long down[maxn];
using ii = pair<int, int>;
vector<ii> g[maxn];
int n, s, q, e;
ii edges[maxn];
bool shop[maxn];
const int LOG = 18;
int up[maxn][LOG];
long long st[maxn][LOG];
using lli = pair<long long, int>;
const long long inf = 1e18;
int T = 0;
int step[maxn];

void dfs(int x, int p, long long he) {
	h[x] = he;
	step[x] = step[p]+1;
	lo[x] = T++;
	down[x] = shop[x] ? 0 : inf;
	for (auto node : g[x]) {
		if (node.first == p) continue;
		dfs(node.first, x, he + node.second);
		down[x] = min(down[x], down[node.first] + node.second);
	}
	hi[x] = T++;
}

void dfs2(int x, int p) {
	st[x][0] = down[x] - h[x];
	up[x][0] = p==0?x:p;
	for (int k = 1; k < LOG; ++k) {
			st[x][k] = min(st[x][k-1], st[up[x][k-1]][k-1]);
			up[x][k] = up[up[x][k-1]][k-1];
	}
	for (auto node : g[x]) {
		if (node.first == p) continue;
		dfs2(node.first, x);
	}
}

bool isParent(int x, int y) {
	return lo[x] <= lo[y] and hi[y] <= hi[x];
}

long long query(int x, int y) {
	int len = step[x] - step[y] + 1;
	long long ans = inf;
	for (int k = 0; k < LOG; ++k) {
		if (len & (1<<k)) {
			ans = min(ans, st[x][k]);
			x = up[x][k];
		}
	}
	return ans;
}

int main() {
	scanf("%d%d%d%d", &n, &s, &q, &e);
	re(i, 1, n) {
		int a, b, w;
		scanf("%d%d%d", &a, &b, &w);
		g[a].eb(b, w);
		g[b].eb(a, w);
		edges[i] = {a, b};
	}
	re(i, 0, s) {
		int c;
		scanf("%d", &c);
		shop[c] = 1;
	}
	dfs(e, 0, 0);
	dfs2(e, 0);
	re(i, 0, q) {
		int I, R;
		scanf("%d%d", &I, &R);
		int a = edges[I].first, b = edges[I].second;
		if (h[a] > h[b]) swap(a, b);
		if (isParent(b, R)) {
			if (down[b] == inf) puts("oo");
			else {
				long long res = query(R, b) + h[R];
				if (res >= inf) puts("oo");
				else printf("%lld\n", res);
			}
		} else puts("escaped");
	}
	return 0;
}

Compilation message

valley.cpp: In function 'int main()':
valley.cpp:66:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d%d", &n, &s, &q, &e);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:69:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d", &a, &b, &w);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~
valley.cpp:76:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &c);
   ~~~~~^~~~~~~~~~
valley.cpp:83:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &I, &R);
   ~~~~~^~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 9 ms 2816 KB Output is correct
2 Correct 9 ms 2816 KB Output is correct
3 Correct 9 ms 2816 KB Output is correct
4 Correct 9 ms 2816 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 9 ms 2816 KB Output is correct
2 Correct 9 ms 2816 KB Output is correct
3 Correct 9 ms 2816 KB Output is correct
4 Correct 9 ms 2816 KB Output is correct
5 Correct 7 ms 3072 KB Output is correct
6 Correct 7 ms 2944 KB Output is correct
7 Correct 7 ms 3072 KB Output is correct
8 Correct 7 ms 3072 KB Output is correct
9 Correct 7 ms 2944 KB Output is correct
10 Correct 7 ms 2944 KB Output is correct
11 Correct 7 ms 3072 KB Output is correct
12 Correct 7 ms 3072 KB Output is correct
13 Correct 7 ms 3072 KB Output is correct
14 Correct 7 ms 3072 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 196 ms 32108 KB Output is correct
2 Correct 201 ms 31736 KB Output is correct
3 Correct 208 ms 31608 KB Output is correct
4 Correct 237 ms 33576 KB Output is correct
5 Correct 213 ms 33528 KB Output is correct
6 Correct 286 ms 35320 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 9 ms 2816 KB Output is correct
2 Correct 9 ms 2816 KB Output is correct
3 Correct 9 ms 2816 KB Output is correct
4 Correct 9 ms 2816 KB Output is correct
5 Correct 7 ms 3072 KB Output is correct
6 Correct 7 ms 2944 KB Output is correct
7 Correct 7 ms 3072 KB Output is correct
8 Correct 7 ms 3072 KB Output is correct
9 Correct 7 ms 2944 KB Output is correct
10 Correct 7 ms 2944 KB Output is correct
11 Correct 7 ms 3072 KB Output is correct
12 Correct 7 ms 3072 KB Output is correct
13 Correct 7 ms 3072 KB Output is correct
14 Correct 7 ms 3072 KB Output is correct
15 Correct 196 ms 32108 KB Output is correct
16 Correct 201 ms 31736 KB Output is correct
17 Correct 208 ms 31608 KB Output is correct
18 Correct 237 ms 33576 KB Output is correct
19 Correct 213 ms 33528 KB Output is correct
20 Correct 286 ms 35320 KB Output is correct
21 Correct 165 ms 31992 KB Output is correct
22 Correct 185 ms 31608 KB Output is correct
23 Correct 195 ms 31608 KB Output is correct
24 Correct 214 ms 33656 KB Output is correct
25 Correct 243 ms 36440 KB Output is correct
26 Correct 175 ms 32248 KB Output is correct
27 Correct 181 ms 31736 KB Output is correct
28 Correct 204 ms 31712 KB Output is correct
29 Correct 243 ms 33140 KB Output is correct
30 Correct 272 ms 34552 KB Output is correct
31 Correct 164 ms 32120 KB Output is correct
32 Correct 194 ms 31936 KB Output is correct
33 Correct 198 ms 31864 KB Output is correct
34 Correct 258 ms 33528 KB Output is correct
35 Correct 250 ms 36376 KB Output is correct
36 Correct 202 ms 34168 KB Output is correct