oj.uz

Submission #549169

# Submission time Handle Problem Language Result Execution time Memory
549169 2022-04-15T10:50:18 Z krit3379 Valley (BOI19_valley) C++17
100 / 100
 200 ms 43832 KB 
#include<bits/stdc++.h>
using namespace std;
#define N 100005

int tin[N],tout[N],depp[N],bp[20][N],t;
long long dp[N],dep[N],mi[20][N],ans;
pair<int,int> edge[N];
vector<pair<int,long long>> g[N];
// dp[i] lowest shop in i subtree

void dfs(int s,int f){
    tin[s]=++t;
    if(dp[s]==-1)dp[s]=dep[s];
    for(auto [x,w]:g[s]){
        if(x==f)continue;
        dep[x]=dep[s]+w;
        dfs(x,s);
        dp[s]=min(dp[s],dp[x]);
    }
    tout[s]=t;
}

void dfs2(int s,int f){
    depp[s]=depp[f]+1;
    bp[0][s]=f;
    mi[0][s]=dp[f]-2*dep[f];
    for(auto [x,w]:g[s]){
        if(x==f)continue;
        dfs2(x,s);
    }
}

int main(){
    int n,s,q,e,a,b,i,j,k,idx,r;
    long long w;
    scanf("%d %d %d %d",&n,&s,&q,&e);
    for(i=1;i<n;i++){
        scanf("%d %d %lld",&a,&b,&w);
        g[a].push_back({b,w});
        g[b].push_back({a,w});
        edge[i]={a,b};
        dp[i]=1e18;
    }
    dp[n]=1e18;
    for(i=1;i<=s;i++){
        scanf("%d",&k);
        dp[k]=-1;
    }
    dfs(e,0);
    dfs2(e,0);
    for(i=1;i<20;i++)for(j=1;j<=n;j++)bp[i][j]=bp[i-1][bp[i-1][j]],mi[i][j]=min(mi[i-1][j],mi[i-1][bp[i-1][j]]);
    while(q--){
        scanf("%d %d",&idx,&r);
        auto [a,b]=edge[idx];
        a=(depp[a]>depp[b])?a:b;
        if(tin[a]<=tin[r]&&tin[r]<=tout[a]){
            int dif=depp[r]-depp[a],temp=r;
            ans=dp[r]-dep[r];
            for(i=0;i<20;i++)if(dif&(1<<i))ans=min(ans,dep[r]+mi[i][temp]),temp=bp[i][temp];
            if(ans>1e16)printf("oo\n");
            else printf("%lld\n",ans);
        }
        else printf("escaped\n");
    }
    return 0;
}

Compilation message

valley.cpp: In function 'int main()':
valley.cpp:36:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |     scanf("%d %d %d %d",&n,&s,&q,&e);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:38:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |         scanf("%d %d %lld",&a,&b,&w);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:46:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |         scanf("%d",&k);
      |         ~~~~~^~~~~~~~~
valley.cpp:53:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   53 |         scanf("%d %d",&idx,&r);
      |         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 3056 KB Output is correct
2 Correct 6 ms 3008 KB Output is correct
3 Correct 5 ms 3028 KB Output is correct
4 Correct 6 ms 3076 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 3056 KB Output is correct
2 Correct 6 ms 3008 KB Output is correct
3 Correct 5 ms 3028 KB Output is correct
4 Correct 6 ms 3076 KB Output is correct
5 Correct 2 ms 3156 KB Output is correct
6 Correct 3 ms 3156 KB Output is correct
7 Correct 3 ms 3156 KB Output is correct
8 Correct 2 ms 3156 KB Output is correct
9 Correct 3 ms 3156 KB Output is correct
10 Correct 3 ms 3156 KB Output is correct
11 Correct 3 ms 3128 KB Output is correct
12 Correct 3 ms 3156 KB Output is correct
13 Correct 3 ms 3156 KB Output is correct
14 Correct 3 ms 3156 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 173 ms 39188 KB Output is correct
2 Correct 131 ms 39040 KB Output is correct
3 Correct 147 ms 39244 KB Output is correct
4 Correct 157 ms 41208 KB Output is correct
5 Correct 175 ms 41316 KB Output is correct
6 Correct 175 ms 43344 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 3056 KB Output is correct
2 Correct 6 ms 3008 KB Output is correct
3 Correct 5 ms 3028 KB Output is correct
4 Correct 6 ms 3076 KB Output is correct
5 Correct 2 ms 3156 KB Output is correct
6 Correct 3 ms 3156 KB Output is correct
7 Correct 3 ms 3156 KB Output is correct
8 Correct 2 ms 3156 KB Output is correct
9 Correct 3 ms 3156 KB Output is correct
10 Correct 3 ms 3156 KB Output is correct
11 Correct 3 ms 3128 KB Output is correct
12 Correct 3 ms 3156 KB Output is correct
13 Correct 3 ms 3156 KB Output is correct
14 Correct 3 ms 3156 KB Output is correct
15 Correct 173 ms 39188 KB Output is correct
16 Correct 131 ms 39040 KB Output is correct
17 Correct 147 ms 39244 KB Output is correct
18 Correct 157 ms 41208 KB Output is correct
19 Correct 175 ms 41316 KB Output is correct
20 Correct 175 ms 43344 KB Output is correct
21 Correct 110 ms 38772 KB Output is correct
22 Correct 180 ms 38536 KB Output is correct
23 Correct 129 ms 38808 KB Output is correct
24 Correct 151 ms 40860 KB Output is correct
25 Correct 200 ms 43832 KB Output is correct
26 Correct 107 ms 38768 KB Output is correct
27 Correct 136 ms 38604 KB Output is correct
28 Correct 151 ms 38780 KB Output is correct
29 Correct 150 ms 40204 KB Output is correct
30 Correct 169 ms 41900 KB Output is correct
31 Correct 129 ms 38732 KB Output is correct
32 Correct 126 ms 38604 KB Output is correct
33 Correct 130 ms 38888 KB Output is correct
34 Correct 180 ms 40800 KB Output is correct
35 Correct 156 ms 43744 KB Output is correct
36 Correct 141 ms 40744 KB Output is correct