Submission #853321

#	Time	Username	Problem	Language	Result	Execution time	Memory
853321		nnhzzz	Harbingers (CEOI09_harbingers)	C++14	100 / 100	101 ms	23008 KiB

harbingers

// cre: Nguyen Ngoc Hung - Train VOI 2024

#include<bits/stdc++.h>

using namespace std;

#define        __nnhzzz__  signed main()
#define          BIT(i,j)  ((i>>j)&1LL)
#define           MASK(i)  (1LL<<i)
#define            ALL(x)  (x).begin(),(x).end()
#define             SZ(x)  (int)(x).size()
#define                fi  first
#define                se  second
#define                ll  long long
#define               ull  unsigned long long
#define                ld  long double
#define                vi  vector<int>
#define               vvi  vector<vi>
#define              vvvi  vector<vvi>
#define               pii  pair<int,int>
#define              vpii  vector<pii>
#define        REP(i,a,b)  for(int i = (a); i<=(b); ++i)
#define       REPD(i,a,b)  for(int i = (a); i>=(b); --i)
#define   REPDIS(i,a,b,c)  for(int i = (a); i<=(b); i+=c)
#define               int  ll
//-------------------------------------------------------------//
const int oo = 1e9,LOG = 20,MAXN = 1e5+7,N = 1e2+3;
const int MOD = 1e9+7,MOD1 = 1e9+207,MOD2 = 1e9+407,MOD3 = 998244353;
//-------------------------------------------------------------//
template<typename T1, typename T2> bool mini(T1 &a, T2 b){if(a>b){a=b;return true;}return false;}
template<typename T1, typename T2> bool maxi(T1 &a, T2 b){if(a<b){a=b;return true;}return false;}

/*
----------------------------------------------------------------
    END OF TEMPLATE
----------------------------------------------------------------
    Nguyen Ngoc Hung - nnhzzz
    Training for VOI24 gold medal
----------------------------------------------------------------
*/

struct Line{
    int m,b;
    Line(){}
    Line(int _m, int _b):m(_m),b(_b){}
    ld isect(const Line &other){ return (ld)(other.b-b)/(ld)(m-other.m);}
    int get(int x){ return m*x+b;}
}st[MAXN];

int dp[MAXN],S[MAXN],V[MAXN];
vpii adj[MAXN];
int top = 0;

int add(Line x){
    int l = 1,r = top+1;
    while(l<r){
        int mid = l+(r-l)/2;
        if(mid>1 && st[mid].isect(x)<=st[mid].isect(st[mid-1])){
            r = mid;
        }else{
            l = mid+1;
        }
    }
    return l;
}

int query(int x){
    int l = 1,r = top;
    while(l<r){
        int mid = l+(r-l+1)/2;
        if(st[mid].isect(st[mid-1])<=x){
            l = mid;
        }else{
            r = mid-1;
        }
    }
    return st[l].get(x);
}

void dfs(int u, int par, int h){
    Line preline; int pretop = 0;
    if(u==0){
        dp[u] = 0; st[++top] = Line(0,0);
    }else{
        dp[u] = query(V[u])+S[u]+V[u]*h;
        Line todo = Line(-h,dp[u]);
        int pos = add(todo);
        preline = st[pos]; pretop = top;
        top = pos; st[top] = todo;
    }
    for(auto [v,w]:adj[u]){
        if(v==par){
            continue;
        }
        dfs(v,u,h+w);
    }
    if(u!=0){
        st[top] = preline;
        top = pretop;
    }
}

void solve(){
    int n; cin >> n;
    REP(i,2,n){
        int u,v,w; cin >> u >> v >> w;
        --u; --v;
        adj[u].emplace_back(v,w);
        adj[v].emplace_back(u,w);
    }
    REP(i,1,n-1){
        cin >> S[i] >> V[i];
    }
    dfs(0,0,0);
    REP(i,1,n-1){
        cout << dp[i] << " ";
    }
}

__nnhzzz__{
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    #define name "test"
    if(fopen(name".inp","r")){
        freopen(name".inp","r",stdin);
        freopen(name".out","w",stdout);
    }
    #define name1 "nnhzzz"
    if(fopen(name1".inp","r")){
        freopen(name1".inp","r",stdin);
        freopen(name1".out","w",stdout);
    }
    int test = 1;
    while(test--){
        solve();
    }
    cerr << "\nTime elapsed: " << 1000*clock()/CLOCKS_PER_SEC << "ms\n";
    return 0;
}

Compilation message (stderr)

harbingers.cpp: In function 'void dfs(long long int, long long int, long long int)':
harbingers.cpp:91:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   91 |     for(auto [v,w]:adj[u]){
      |              ^
harbingers.cpp: In function 'int main()':
harbingers.cpp:125:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  125 |         freopen(name".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
harbingers.cpp:126:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  126 |         freopen(name".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
harbingers.cpp:130:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  130 |         freopen(name1".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
harbingers.cpp:131:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  131 |         freopen(name1".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100