Submission #240958

#	Time	Username	Problem	Language	Result	Execution time	Memory
240958		rqi	Election Campaign (JOI15_election_campaign)	C++14	100 / 100	632 ms	73064 KiB

election_campaign

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef double db; 
typedef string str; 

typedef pair<int,int> pi;
typedef pair<ll,ll> pl; 
typedef pair<db,db> pd; 

typedef vector<int> vi; 
typedef vector<ll> vl; 
typedef vector<db> vd; 
typedef vector<str> vs; 
typedef vector<pi> vpi;
typedef vector<pl> vpl; 
typedef vector<pd> vpd; 

#define mp make_pair
#define f first
#define s second
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend() 
#define rsz resize
#define ins insert 
#define ft front() 
#define bk back()
#define pf push_front 
#define pb push_back
#define eb emplace_back 
#define lb lower_bound 
#define ub upper_bound 

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5; 
const ll INF = 1e18; 
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; 
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 

template<class T> bool ckmin(T& a, const T& b) { 
    return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { 
    return a < b ? a = b, 1 : 0; } 
int pct(int x) { return __builtin_popcount(x); } 
int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
int cdiv(int a, int b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0 
int fstTrue(function<bool(int)> f, int lo, int hi) {
    hi ++; assert(lo <= hi); // assuming f is increasing
    while (lo < hi) { // find first index such that f is true 
        int mid = (lo+hi)/2; 
        f(mid) ? hi = mid : lo = mid+1; 
    } 
    return lo;
}

// INPUT
template<class A> void re(complex<A>& c);
template<class A, class B> void re(pair<A,B>& p);
template<class A> void re(vector<A>& v);
template<class A, size_t SZ> void re(array<A,SZ>& a);

template<class T> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); }

template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; }
template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); }
template<class A> void re(vector<A>& x) { trav(a,x) re(a); }
template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); }

// TO_STRING
#define ts to_string
str ts(char c) { return str(1,c); }
str ts(bool b) { return b ? "true" : "false"; }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
template<class A> str ts(complex<A> c) { 
    stringstream ss; ss << c; return ss.str(); }
str ts(vector<bool> v) { 
    str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]);
    res += "}"; return res; }
template<size_t SZ> str ts(bitset<SZ> b) {
    str res = ""; F0R(i,SZ) res += char('0'+b[i]);
    return res; }
template<class A, class B> str ts(pair<A,B> p);
template<class T> str ts(T v) { // containers with begin(), end()
    bool fst = 1; str res = "{";
    for (const auto& x: v) {
        if (!fst) res += ", ";
        fst = 0; res += ts(x);
    }
    res += "}"; return res;
}
template<class A, class B> str ts(pair<A,B> p) {
    return "("+ts(p.f)+", "+ts(p.s)+")"; }

// OUTPUT
template<class A> void pr(A x) { cout << ts(x); }
template<class H, class... T> void pr(const H& h, const T&... t) { 
    pr(h); pr(t...); }
void ps() { pr("\n"); } // print w/ spaces
template<class H, class... T> void ps(const H& h, const T&... t) { 
    pr(h); if (sizeof...(t)) pr(" "); ps(t...); }

// DEBUG
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << ts(h); if (sizeof...(t)) cerr << ", ";
    DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif

// FILE I/O
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { ios_base::sync_with_stdio(0); cin.tie(0); }
void setIO(string s = "") {
    unsyncIO();
    // cin.exceptions(cin.failbit); 
    // throws exception when do smth illegal
    // ex. try to read letter into int
    if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
}


/**
 * Description: 1D range minimum query. Can also do queries 
     * for any associative operation in $O(1)$ with D\&C
 * Source: KACTL
 * Verification: 
    * https://cses.fi/problemset/stats/1647/
    * http://wcipeg.com/problem/ioi1223
    * https://pastebin.com/ChpniVZL
 * Memory: O(N\log N)
 * Time: O(1)
 */

template<class T> struct RMQ { // floor(log_2(x))
    int level(int x) { return 31-__builtin_clz(x); } 
    vector<T> v; vector<vi> jmp;
    int comb(int a, int b) { // index of min
        return v[a]==v[b]?min(a,b):(v[a]<v[b]?a:b); } 
    void init(const vector<T>& _v) {
        v = _v; jmp = {vi(sz(v))}; iota(all(jmp[0]),0);
        for (int j = 1; 1<<j <= sz(v); ++j) {
            jmp.pb(vi(sz(v)-(1<<j)+1));
            F0R(i,sz(jmp[j])) jmp[j][i] = comb(jmp[j-1][i],
                                    jmp[j-1][i+(1<<(j-1))]);
        }
    }
    int index(int l, int r) { // get index of min element
        int d = level(r-l+1);
        return comb(jmp[d][l],jmp[d][r-(1<<d)+1]); }
    T query(int l, int r) { return v[index(l,r)]; }
};



template<int SZ> struct LCA {
    int N, R = 1, depth[SZ], st[SZ];
    vi adj[SZ]; vpi tmp; RMQ<pi> r;
    void ae(int u, int v) { adj[u].pb(v), adj[v].pb(u); }
    void dfs(int u, int p) {
        st[u] = sz(tmp), depth[u] = depth[p]+1;
        tmp.eb(depth[u],u); 
        trav(v,adj[u]) if (v != p) 
            dfs(v,u), tmp.eb(depth[u],u);
    }
    void init(int _N) { N = _N; dfs(R,0); r.init(tmp); }
    int lca(int u, int v){
        u = st[u], v = st[v]; if (u > v) swap(u,v);
        return r.query(u,v).s; }
    /// int dist(int u, int v) {
        /// return depth[u]+depth[v]-2*depth[lca(u,v)]; }
    vpi compress(vi S) {
        static vi rev; rev.rsz(N+1);
        auto cmp = [&](int a, int b) { return st[a] < st[b]; };
        sort(all(S),cmp); R0F(i,sz(S)-1) S.pb(lca(S[i],S[i+1]));
        sort(all(S),cmp); S.erase(unique(all(S)),end(S));
        vpi ret{{0,S[0]}}; F0R(i,sz(S)) rev[S[i]] = i;
        F0R(i,sz(S)-1) ret.eb(rev[lca(S[i],S[i+1])],S[i+1]);
        return ret;
    }
};


/**
 * Description: 1D range update and query, $SZ=2^p$.
 * Source: USACO Counting Haybales
 * Verification: SPOJ Horrible
 */

template<class T, int SZ> struct LazySeg { 
    T sum[2*SZ], lazy[2*SZ]; 
    LazySeg() { F0R(i,2*SZ) sum[i] = lazy[i] = 0; }
    void push(int ind, int L, int R) { /// modify values for current node
        if (L != R) F0R(i,2) lazy[2*ind+i] += lazy[ind]; /// prop to children
        sum[ind] += (R-L+1)*lazy[ind]; lazy[ind] = 0; 
    } // recalc values for current node
    void pull(int ind) { sum[ind] = sum[2*ind]+sum[2*ind+1]; }
    void build() { ROF(i,1,SZ) pull(i); }
    void upd(int lo,int hi,T inc,int ind=1,int L=0, int R=SZ-1) {
        push(ind,L,R); if (hi < L || R < lo) return;
        if (lo <= L && R <= hi) { 
            lazy[ind] = inc; push(ind,L,R); return; }
        int M = (L+R)/2; upd(lo,hi,inc,2*ind,L,M); 
        upd(lo,hi,inc,2*ind+1,M+1,R); pull(ind);
    }
    T qsum(int lo, int hi, int ind=1, int L=0, int R = SZ-1) {
        push(ind,L,R); if (lo > R || L > hi) return 0;
        if (lo <= L && R <= hi) return sum[ind];
        int M = (L+R)/2; 
        return qsum(lo,hi,2*ind,L,M)+qsum(lo,hi,2*ind+1,M+1,R);
    }
};


template<int SZ, bool VALS_IN_EDGES> struct HLD { 
    int N; vi adj[SZ];
    int par[SZ], sz[SZ], depth[SZ];
    int root[SZ], pos[SZ]; /// vi rpos;
    void ae(int a, int b) { adj[a].pb(b), adj[b].pb(a); }
    void dfsSz(int v = 1) {
        if (par[v]) adj[v].erase(find(all(adj[v]),par[v]));
        sz[v] = 1;
        trav(u,adj[v]) {
            par[u] = v; depth[u] = depth[v]+1;
            dfsSz(u); sz[v] += sz[u];
            if (sz[u] > sz[adj[v][0]]) swap(u, adj[v][0]);
        }
    }
    void dfsHld(int v = 1) {
        static int t = 0; pos[v] = t++; /// rpos.pb(v);
        trav(u,adj[v]) {
            root[u] = (u == adj[v][0] ? root[v] : u);
            dfsHld(u); }
    }
    void init(int _N) {
        N = _N; par[1] = depth[1] = 0; root[1] = 1; 
        dfsSz(); dfsHld(); }
    LazySeg<ll,SZ> tree;
    template <class BinaryOp>
    void processPath(int u, int v, BinaryOp op) {
        for (; root[u] != root[v]; v = par[root[v]]) {
            if (depth[root[u]] > depth[root[v]]) swap(u, v);
            op(pos[root[v]], pos[v]); }
        if (depth[u] > depth[v]) swap(u, v);
        op(pos[u]+VALS_IN_EDGES, pos[v]); 
    }
    void modifyPath(int u, int v, int val) { 
        processPath(u,v,[this, &val](int l,int r) { 
            tree.upd(l,r,val); }); }
    void modifySubtree(int v, int val) { 
        tree.upd(pos[v]+VALS_IN_EDGES,pos[v]+sz[v]-1,val); }
    ll queryPath(int u, int v) { 
        ll res = 0; processPath(u,v,[this,&res](int l,int r) { 
            res += tree.qsum(l,r); });
        return res; }
};



const int mx = 131072;
int N, M;
vi adj[mx];
int A[mx];
int B[mx];
int C[mx];
vi queries[mx];
int dp1[mx];
int dp2[mx];
LCA<mx> lca;
HLD<mx, false> hld; 

void solve(int node, int prv = -1){
    for(auto u: adj[node]){
        if(u == prv) continue;
        solve(u, node);
        dp2[node]+=dp1[u];
    }
    hld.modifyPath(node, node, dp2[node]);
    int curans = dp2[node];
    for(auto u: queries[node]){
        ckmax(curans, int(hld.queryPath(A[u], B[u])+C[u]));
    }
    dp1[node] = curans;
    hld.modifyPath(node, node, -dp1[node]);
}

int main() {
    setIO();
    cin >> N;
    for(int i = 1; i <= N-1; i++){
        int X, Y;
        cin >> X >> Y;
        adj[X].pb(Y);
        adj[Y].pb(X);
        lca.ae(X, Y);
        hld.ae(X, Y);
    }
    lca.init(N);
    hld.init(N);
    cin >> M;
    for(int i = 1; i <= M; i++){
        cin >> A[i] >> B[i] >> C[i];
        queries[lca.lca(A[i], B[i])].pb(i);
    }
    solve(1);
    ps(dp1[1]);
    // you should actually read the stuff at the bottom
}

/* stuff you should look for
    * int overflow, array bounds
    * special cases (n=1?)
    * do smth instead of nothing and stay organized
    * WRITE STUFF DOWN
*/

Compilation message (stderr)

election_campaign.cpp: In function 'void setIn(std::__cxx11::string)':
election_campaign.cpp:128:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setIn(string s) { freopen(s.c_str(),"r",stdin); }
                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
election_campaign.cpp: In function 'void setOut(std::__cxx11::string)':
election_campaign.cpp:129:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setOut(string s) { freopen(s.c_str(),"w",stdout); }
                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 30 / 30
• Subtask 5: 10 / 10
• Subtask 6: 40 / 40