oj.uz

Submission #125007

# Submission time Handle Problem Language Result Execution time Memory
125007 2019-07-04T10:46:28 Z gs14004 Valley (BOI19_valley) C++17
100 / 100
 227 ms 36992 KB 
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100005;
using lint = long long;
using pi = pair<int, int>;

struct edg{
	int s, e, x;
}ed[MAXN];

vector<pi> gph[MAXN];
int n, m, q, r, din[MAXN], dout[MAXN], lvl[MAXN], piv;
lint dp[MAXN], dep[MAXN];
int par[17][MAXN];
lint spt[17][MAXN];

bool sub(int s, int e){
	return din[s] <= din[e] && dout[e] <= dout[s];
}

void dfs(int x, int p){
	din[x] = ++piv;
	for(auto &i : gph[x]){
		if(i.second == p) continue;
		dep[i.second] = dep[x] + i.first;
		lvl[i.second] = lvl[x] + 1;
		par[0][i.second] = x;
		dfs(i.second, x);
		dp[x] = min(dp[x], dp[i.second] + i.first);
	}
	dout[x] = piv;
}

int main(){
	scanf("%d %d %d %d",&n,&m,&q,&r);
	for(int i=1; i<n; i++){
		scanf("%d %d %d",&ed[i].s,&ed[i].e,&ed[i].x);
		gph[ed[i].s].emplace_back(ed[i].x, ed[i].e);
		gph[ed[i].e].emplace_back(ed[i].x, ed[i].s);
	}
	memset(dp, 0x3f, sizeof(dp));
	while(m--){
		int x; scanf("%d",&x); dp[x] = 0;
	}
	dfs(r, -1);
	for(int i=1; i<n; i++){
		if(par[0][ed[i].s] == ed[i].e) swap(ed[i].s, ed[i].e);
	}
	for(int i=1; i<=n; i++){
		spt[0][i] = dp[i] - dep[i];
	}
	for(int i=1; i<17; i++){
		for(int j=1; j<=n; j++){
			par[i][j] = par[i-1][par[i-1][j]];
			spt[i][j] = min(spt[i-1][j], spt[i-1][par[i-1][j]]);
		}
	}
	while(q--){
		int idx, pos;
		scanf("%d %d",&idx,&pos);
		idx = ed[idx].e;
		if(!sub(idx, pos)){
			puts("escaped");
			continue;
		}
		lint ret = 1e18;
		int step = lvl[pos] - lvl[idx] + 1;
		int opo = pos;
		for(int i=0; i<17; i++){
			if((step >> i) & 1){
				ret = min(ret, spt[i][pos]);
				pos = par[i][pos];
			}
		}
		ret += dep[opo];
		if(ret > 1e17) puts("oo");
		else printf("%lld\n", ret);
	}
}

Compilation message

valley.cpp: In function 'int main()':
valley.cpp:35:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %d %d",&n,&m,&q,&r);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:37:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d %d",&ed[i].s,&ed[i].e,&ed[i].x);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:43:15: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int x; scanf("%d",&x); dp[x] = 0;
          ~~~~~^~~~~~~~~
valley.cpp:60:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&idx,&pos);
   ~~~~~^~~~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 3804 KB Output is correct
2 Correct 8 ms 3832 KB Output is correct
3 Correct 7 ms 3836 KB Output is correct
4 Correct 8 ms 3832 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 3804 KB Output is correct
2 Correct 8 ms 3832 KB Output is correct
3 Correct 7 ms 3836 KB Output is correct
4 Correct 8 ms 3832 KB Output is correct
5 Correct 6 ms 3932 KB Output is correct
6 Correct 6 ms 3960 KB Output is correct
7 Correct 6 ms 3960 KB Output is correct
8 Correct 6 ms 3960 KB Output is correct
9 Correct 6 ms 3960 KB Output is correct
10 Correct 6 ms 3960 KB Output is correct
11 Correct 6 ms 3960 KB Output is correct
12 Correct 6 ms 3960 KB Output is correct
13 Correct 6 ms 3960 KB Output is correct
14 Correct 6 ms 3964 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 168 ms 35064 KB Output is correct
2 Correct 192 ms 34680 KB Output is correct
3 Correct 190 ms 34592 KB Output is correct
4 Correct 215 ms 35668 KB Output is correct
5 Correct 189 ms 35832 KB Output is correct
6 Correct 227 ms 36684 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 3804 KB Output is correct
2 Correct 8 ms 3832 KB Output is correct
3 Correct 7 ms 3836 KB Output is correct
4 Correct 8 ms 3832 KB Output is correct
5 Correct 6 ms 3932 KB Output is correct
6 Correct 6 ms 3960 KB Output is correct
7 Correct 6 ms 3960 KB Output is correct
8 Correct 6 ms 3960 KB Output is correct
9 Correct 6 ms 3960 KB Output is correct
10 Correct 6 ms 3960 KB Output is correct
11 Correct 6 ms 3960 KB Output is correct
12 Correct 6 ms 3960 KB Output is correct
13 Correct 6 ms 3960 KB Output is correct
14 Correct 6 ms 3964 KB Output is correct
15 Correct 168 ms 35064 KB Output is correct
16 Correct 192 ms 34680 KB Output is correct
17 Correct 190 ms 34592 KB Output is correct
18 Correct 215 ms 35668 KB Output is correct
19 Correct 189 ms 35832 KB Output is correct
20 Correct 227 ms 36684 KB Output is correct
21 Correct 150 ms 34424 KB Output is correct
22 Correct 161 ms 34012 KB Output is correct
23 Correct 168 ms 34176 KB Output is correct
24 Correct 181 ms 35192 KB Output is correct
25 Correct 193 ms 36992 KB Output is correct
26 Correct 191 ms 34552 KB Output is correct
27 Correct 161 ms 34040 KB Output is correct
28 Correct 171 ms 34012 KB Output is correct
29 Correct 189 ms 34936 KB Output is correct
30 Correct 220 ms 35964 KB Output is correct
31 Correct 157 ms 33396 KB Output is correct
32 Correct 173 ms 30960 KB Output is correct
33 Correct 170 ms 30908 KB Output is correct
34 Correct 184 ms 31964 KB Output is correct
35 Correct 193 ms 33656 KB Output is correct
36 Correct 172 ms 32504 KB Output is correct