Submission #1214027

#	Time	Username	Problem	Language	Result	Execution time	Memory
1214027		trinm01	Harbingers (CEOI09_harbingers)	C++20	10 / 100	85 ms	24904 KiB

harbingers

#include <bits/stdc++.h>
using namespace std;

// #define int long long
#define ll long long
#define FOR(i, l, r) for (int i = (l); i <= (r); i++)
#define FOD(i, r, l) for (int i = (r); i >= (l); i--)
#define fi first
#define se second
#define pii pair<int, int>

const ll mod = 1e9 + 7;
const ll MAXN = 1e5 + 5;
const int oo = 1e18;
const int base = 320;

int n, s[MAXN], p[MAXN], d[MAXN];
vector<pii> adj[MAXN];

ll f[MAXN];
vector<int> A, B, xoaA[MAXN], xoaB[MAXN];
bool bad(int l1, int l2, int l3){
    return (B[l3]-B[l1])*(A[l1]-A[l2])<(B[l2]-B[l1])*(A[l1]-A[l3]);
}
void add(int a, int b, int u){
    // if(u==7){
    //     for(auto x:A){
    //         cout << x << ' ';
    //     }
    //     cout << '\n';
    // }
    A.push_back(a);
    B.push_back(b);
    
    while((int)A.size()>=3 && bad(A.size()-3, A.size()-2, A.size()-1)){
        xoaA[u].push_back(A[A.size()-2]);
        xoaB[u].push_back(B[B.size()-2]);
        A.erase(A.end()-2);
        B.erase(B.end()-2);
    }
    // if(u==9){
    //     for(auto x:A){
    //         cout << x << ' ';
    //     }
    //     cout << '\n';
    //     for(auto x:B){
    //         cout << x << ' ';
    //     }
    //     cout << '\n';
    // }
}
void hoi(int a, int b, int u){
    A.pop_back();
    B.pop_back();
    FOD(i, (int)xoaA[u].size()-1, 0){
        A.push_back(xoaA[u][i]);
        B.push_back(xoaB[u][i]);
    }
    xoaA[u].clear();
    xoaB[u].clear();
    // if(u==7){
    //     for(auto x:A){
    //         cout << x << ' ';
    //     }
    //     cout << '\n';
    // }
}
ll query(int x){
    int l=1, r=(int)A.size()-1, id=1;
    if(r==-1){
        return 0;
    }
    if(r==0){
        return A[0]*x+B[0];
    }
    ll ans=oo;
    while(l<=r){
        int mid=(l+r)/2;
        if(A[mid]*x+B[mid]<A[mid-1]*x+B[mid-1]){
            id=mid;
            l=mid+1;
            ans=min(ans, (ll)(A[mid]*x+B[mid]));
        }
        else{
            r=mid-1;
            ans=min(ans, (ll)(A[mid-1]+B[mid-1]));
        }
    }
    // if(x==6)cout << id << '\n';
    ans=min({ans, (ll)(A[id]*x+B[id]), (ll)(A[id-1]*x+B[id-1])});
    if(id!=A.size()-1){
        ans=min(ans, (ll)(A[id+1]*x+B[id+1]));
    }
    return ans;
}

void dfs2(int u, int last){
    if(u!=1){
        f[u]=query(p[u])+d[u]*p[u]+s[u];
        // if(u==4) cout << query(p[u]) << ' ';
    }
    add(-d[u], f[u], u);

    for(auto [v, c]:adj[u]){
        if(v==last) continue;
        d[v]=d[u]+c;
        dfs2(v, u);
    }

    hoi(-d[u], f[u], u);
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    if (fopen(".INP", "r"))
    {
        freopen(".INP", "r", stdin);
        freopen(".OUT", "w", stdout);
    }       

    cin >> n;
    FOR(i, 1, n-1){
        int u, v, c;
        cin >> u >> v >> c;
        adj[u].push_back({v, c});
        adj[v].push_back({u, c});
    }
    FOR(i, 2, n){
        cin >> s[i] >> p[i];    
    }

    dfs2(1, 1);
    FOR(i, 2, n){
        cout << f[i] << ' ';
    }


    return 0;
}

Compilation message (stderr)

harbingers.cpp:14:16: warning: overflow in conversion from 'double' to 'int' changes value from '1.0e+18' to '2147483647' [-Woverflow]
   14 | const int oo = 1e18;
      |                ^~~~
harbingers.cpp: In function 'int main()':
harbingers.cpp:120:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  120 |         freopen(".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~
harbingers.cpp:121:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  121 |         freopen(".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 100