oj.uz

Submission #414792

# Submission time Handle Problem Language Result Execution time Memory
414792 2021-05-31T08:01:29 Z juggernaut The Xana coup (BOI21_xanadu) C++17
100 / 100
 120 ms 31180 KB 
#include<bits/stdc++.h>
#define fr first
#define sc second
using namespace std;
void usaco(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
typedef long long ll;
#define USING_ORDERED_SET 0
#if USING_ORDERED_SET
#include<bits/extc++.h>
using namespace __gnu_pbds;
template<class T>using ordered_set=tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
#endif
template<class T>void umax(T &a,T b){if(a<b)a=b;}
template<class T>void umin(T &a,T b){if(b<a)a=b;}
#ifdef IOI2021SG
    #define printl(args...)printf(args)
#else
    #define printl(args...)((void)0)
#endif
int a[100005],n;
vector<int>g[100005];
ll dp[100005][2][2];
struct knapsack{
    ll odd,even;
    ll sum;
    knapsack(){
        sum=0;
        odd=even=2e5;
    }
    vector<int>v;
    void add(int without,int with){
        v.push_back(with-without);
        sum+=without;
    }
    void build(){
        sort(v.begin(),v.end());
        umin(even,sum);
        ll pref=sum;
        for(int i=0;i<v.size();i++){
            pref+=v[i];
            if(i&1){
                umin(even,pref);
            }else{
                umin(odd,pref);
            }
        }
    }
};
void dfs(int v,int p){
    dp[v][0][0]=2e5;
    dp[v][0][1]=2e5;
    dp[v][1][0]=2e5;
    dp[v][1][1]=2e5;
    for(int to:g[v])if(to!=p)dfs(to,v);
    int sz=g[v].size();
    if(v^p)sz--;
    if(sz==0){
        if(a[v]==0){
            dp[v][0][0]=0;
            dp[v][0][1];
            dp[v][1][0];
            dp[v][1][1]=1;
        }else{
            dp[v][0][0];
            dp[v][0][1]=0;
            dp[v][1][0]=1;
            dp[v][1][1];
        }
    }else{
        knapsack a,b;
        for(int to:g[v])if(to!=p){
            a.add(dp[to][0][0],dp[to][1][0]);
            b.add(dp[to][0][1],dp[to][1][1]);
        }
        a.build();
        b.build();
        if(::a[v]==0){
            dp[v][0][0]=a.even;
            dp[v][0][1]=a.odd;
            dp[v][1][0]=b.odd+1;
            dp[v][1][1]=b.even+1;
        }else{
            dp[v][0][0]=a.odd;
            dp[v][0][1]=a.even;
            dp[v][1][0]=b.even+1;
            dp[v][1][1]=b.odd+1;
        }
    }
    /*
    if(sz==0){
        if(a[v]==0){
            dp[v][0][0]=0;
            dp[v][0][1];
            dp[v][1][0];
            dp[v][1][1]=1;
        }else{
            dp[v][0][0];
            dp[v][0][1]=0;
            dp[v][1][0]=1;
            dp[v][1][1];
        }
    }else if(sz==1){
        if(a[v]==0){
            dp[v][0][0]=dp[x][0][0];
            dp[v][0][1]=dp[x][1][0];
            dp[v][1][0]=dp[x][1][1]+1;
            dp[v][1][1]=dp[x][0][1]+1;
        }else{
            dp[v][0][0]=dp[x][1][0];
            dp[v][0][1]=dp[x][0][0];
            dp[v][1][0]=dp[x][0][1]+1;
            dp[v][1][1]=dp[x][1][1]+1;
        }
    }else if(sz==2){
        if(a[v]==0){
            dp[v][0][0]=min(dp[x][0][0]+dp[y][0][0],dp[x][1][0]+dp[y][1][0]);
            dp[v][0][1]=min(dp[x][1][0]+dp[y][0][0],dp[x][0][0]+dp[y][1][0]);
            dp[v][1][0]=min(dp[x][1][1]+dp[y][0][1],dp[x][0][1]+dp[y][1][1])+1;
            dp[v][1][1]=min(dp[x][0][1]+dp[y][0][1],dp[x][1][1]+dp[y][1][1])+1;
        }else{
            dp[v][0][0]=min(dp[x][1][0]+dp[y][0][0],dp[x][0][0]+dp[y][1][0]);
            dp[v][0][1]=min(dp[x][0][0]+dp[y][0][0],dp[x][1][0]+dp[y][1][0]);
            dp[v][1][0]=min(dp[x][0][1]+dp[y][0][1],dp[x][1][1]+dp[y][1][1])+1;
            dp[v][1][1]=min(dp[x][1][1]+dp[y][0][1],dp[x][0][1]+dp[y][1][1])+1;
        }
    }
    */
}
int main(){
    scanf("%d",&n);
    for(int i=1,x,y;i<n;i++){
        scanf("%d%d",&x,&y);
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for(int i=1;i<=n;i++)scanf("%d",&a[i]);
    dfs(1,1);
    int x=min(dp[1][1][0],dp[1][0][0]);
    if(x>=int(2e5))puts("impossible");
    else printf("%d",x);
}

Compilation message

xanadu.cpp: In member function 'void knapsack::build()':
xanadu.cpp:39:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |         for(int i=0;i<v.size();i++){
      |                     ~^~~~~~~~~
xanadu.cpp: In function 'void dfs(int, int)':
xanadu.cpp:60:23: warning: statement has no effect [-Wunused-value]
   60 |             dp[v][0][1];
      |             ~~~~~~~~~~^
xanadu.cpp:61:23: warning: statement has no effect [-Wunused-value]
   61 |             dp[v][1][0];
      |             ~~~~~~~~~~^
xanadu.cpp:64:23: warning: statement has no effect [-Wunused-value]
   64 |             dp[v][0][0];
      |             ~~~~~~~~~~^
xanadu.cpp:67:23: warning: statement has no effect [-Wunused-value]
   67 |             dp[v][1][1];
      |             ~~~~~~~~~~^
xanadu.cpp: In function 'void usaco(std::string)':
xanadu.cpp:5:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | void usaco(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
xanadu.cpp:5:66: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | void usaco(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
      |                                                           ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
xanadu.cpp: In function 'int main()':
xanadu.cpp:130:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  130 |     scanf("%d",&n);
      |     ~~~~~^~~~~~~~~
xanadu.cpp:132:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  132 |         scanf("%d%d",&x,&y);
      |         ~~~~~^~~~~~~~~~~~~~
xanadu.cpp:136:31: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  136 |     for(int i=1;i<=n;i++)scanf("%d",&a[i]);
      |                          ~~~~~^~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 2 ms 2636 KB Output is correct
3 Correct 2 ms 2636 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 2 ms 2636 KB Output is correct
3 Correct 2 ms 2636 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct
6 Correct 2 ms 2636 KB Output is correct
7 Correct 2 ms 2636 KB Output is correct
8 Correct 2 ms 2636 KB Output is correct
9 Correct 2 ms 2636 KB Output is correct
10 Correct 3 ms 2636 KB Output is correct
11 Correct 3 ms 2636 KB Output is correct
12 Correct 2 ms 2636 KB Output is correct
13 Correct 2 ms 2636 KB Output is correct
14 Correct 2 ms 2636 KB Output is correct
15 Correct 2 ms 2636 KB Output is correct
16 Correct 2 ms 2636 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 96 ms 31048 KB Output is correct
2 Correct 90 ms 30608 KB Output is correct
3 Correct 97 ms 31180 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 94 ms 30984 KB Output is correct
2 Correct 99 ms 30700 KB Output is correct
3 Correct 97 ms 31160 KB Output is correct
4 Correct 73 ms 8504 KB Output is correct
5 Correct 90 ms 9156 KB Output is correct
6 Correct 100 ms 9180 KB Output is correct
7 Correct 2 ms 2636 KB Output is correct
8 Correct 25 ms 5004 KB Output is correct
9 Correct 88 ms 9412 KB Output is correct
10 Correct 80 ms 9428 KB Output is correct
11 Correct 89 ms 10940 KB Output is correct
12 Correct 97 ms 11352 KB Output is correct
13 Correct 82 ms 8768 KB Output is correct
14 Correct 88 ms 9204 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 2 ms 2636 KB Output is correct
3 Correct 2 ms 2636 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct
6 Correct 2 ms 2636 KB Output is correct
7 Correct 2 ms 2636 KB Output is correct
8 Correct 2 ms 2636 KB Output is correct
9 Correct 2 ms 2636 KB Output is correct
10 Correct 3 ms 2636 KB Output is correct
11 Correct 3 ms 2636 KB Output is correct
12 Correct 2 ms 2636 KB Output is correct
13 Correct 2 ms 2636 KB Output is correct
14 Correct 2 ms 2636 KB Output is correct
15 Correct 2 ms 2636 KB Output is correct
16 Correct 2 ms 2636 KB Output is correct
17 Correct 96 ms 31048 KB Output is correct
18 Correct 90 ms 30608 KB Output is correct
19 Correct 97 ms 31180 KB Output is correct
20 Correct 94 ms 30984 KB Output is correct
21 Correct 99 ms 30700 KB Output is correct
22 Correct 97 ms 31160 KB Output is correct
23 Correct 73 ms 8504 KB Output is correct
24 Correct 90 ms 9156 KB Output is correct
25 Correct 100 ms 9180 KB Output is correct
26 Correct 2 ms 2636 KB Output is correct
27 Correct 25 ms 5004 KB Output is correct
28 Correct 88 ms 9412 KB Output is correct
29 Correct 80 ms 9428 KB Output is correct
30 Correct 89 ms 10940 KB Output is correct
31 Correct 97 ms 11352 KB Output is correct
32 Correct 82 ms 8768 KB Output is correct
33 Correct 88 ms 9204 KB Output is correct
34 Correct 2 ms 2636 KB Output is correct
35 Correct 2 ms 2636 KB Output is correct
36 Correct 2 ms 2636 KB Output is correct
37 Correct 2 ms 2636 KB Output is correct
38 Correct 2 ms 2636 KB Output is correct
39 Correct 2 ms 2636 KB Output is correct
40 Correct 2 ms 2636 KB Output is correct
41 Correct 3 ms 2636 KB Output is correct
42 Correct 2 ms 2636 KB Output is correct
43 Correct 2 ms 2636 KB Output is correct
44 Correct 2 ms 2636 KB Output is correct
45 Correct 92 ms 31016 KB Output is correct
46 Correct 85 ms 30708 KB Output is correct
47 Correct 94 ms 31160 KB Output is correct
48 Correct 67 ms 8472 KB Output is correct
49 Correct 78 ms 9132 KB Output is correct
50 Correct 89 ms 9284 KB Output is correct
51 Correct 2 ms 2580 KB Output is correct
52 Correct 27 ms 5020 KB Output is correct
53 Correct 120 ms 9336 KB Output is correct
54 Correct 104 ms 9540 KB Output is correct
55 Correct 87 ms 10972 KB Output is correct
56 Correct 84 ms 11296 KB Output is correct
57 Correct 75 ms 8916 KB Output is correct
58 Correct 75 ms 9156 KB Output is correct
59 Correct 27 ms 4928 KB Output is correct
60 Correct 73 ms 8820 KB Output is correct
61 Correct 77 ms 9264 KB Output is correct
62 Correct 95 ms 9420 KB Output is correct
63 Correct 90 ms 9524 KB Output is correct
64 Correct 80 ms 9412 KB Output is correct
65 Correct 83 ms 9792 KB Output is correct
66 Correct 68 ms 9756 KB Output is correct
67 Correct 68 ms 10920 KB Output is correct
68 Correct 64 ms 12376 KB Output is correct
69 Correct 68 ms 12248 KB Output is correct
70 Correct 69 ms 12220 KB Output is correct