Submission #1063218

#	Time	Username	Problem	Language	Result	Execution time	Memory
1063218		Beerus13	Constellation 3 (JOI20_constellation3)	C++17	100 / 100	261 ms	92500 KiB

constellation3

#include<bits/stdc++.h>
using namespace std;
#define FOR(i, a, b)  for(int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, b, a) for(int i = (b), _a = (a); i >= _a; --i)
#define REP(i, a, b)  for(int i = (a), _b = (b); i < _b;  ++i)
#define REPD(i, b, a) for(int i = (b), _a = (a); i > _a;  --i)
#define MASK(i) (1LL << (i))
#define BIT(mask, i) (((mask) >> (i)) & 1)
#define __builtin_popcount __builtin_popcountll
#define all(val) val.begin(), val.end()
#define ll long long
#define ull unsigned long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define sz(v) (int)v.size()
#define fi first
#define se second

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll Rand(ll l, ll r) {return l + rng() % (r - l + 1);}

template<class X, class Y>
    bool minimize(X &x, const Y &y) {
        if (x > y) {
            x = y;
            return true;
        } else return false;
    }
template<class X, class Y>
    bool maximize(X &x, const Y &y) {
        if (x < y) {
            x = y;
            return true;
        } else return false;
    }
template<class T>
    T Abs(const T &x) {
        return (x < 0 ? -x : x);    
    }

const int mod = 1e9 + 7;
const int inf = 1e9;
const int N = 2e5 + 5;
const int K = 19;

struct fenwicktree {
    int n;
    vector<ll> bit;
    fenwicktree(int _n) {
        n = _n;
        bit.assign(n + 1, 0);
    }

    void upd(int i, ll val) {
        for(; i <= n; i += i & -i) bit[i] += val;
    }

    void upd(int l, int r, ll val) {
        upd(l, val);
        upd(r + 1, -val);
    }

    ll get(int i) {
        ll res(0);
        for(; i; i -= i & -i) res += bit[i];
        return res;
    }
};

int n, m, timeDFS;
int a[N], P[N][K], in[N], out[N];
vector<int> g[N];
vector<pii> stars[N];
pii rmq[N][K];
ll dp[N];

int getroot(int l, int r) {
    int k = 31 - __builtin_clz(r - l + 1);
    return -max(rmq[l][k], rmq[r - MASK(k) + 1][k]).se;
}

int dfs(int l, int r, int par = 0) {
    if(l > r) return 0;
    int root = getroot(l, r);

    in[root] = ++timeDFS;
    g[par].push_back(root);
    P[root][0] = par;
    REP(i, 1, K) P[root][i] = P[P[root][i - 1]][i - 1];

    dfs(l, root - 1, root);
    dfs(root + 1, r, root);
    out[root] = timeDFS;
    return root;
}

void process() {
    cin >> n;
    FOR(i, 1, n) {
        cin >> a[i];
        rmq[i][0] = {a[i], -i};
    }
    REP(j, 1, K) FOR(i, 1, n - MASK(j) + 1) {
        rmq[i][j] = max(rmq[i][j - 1], rmq[i + MASK(j - 1)][j - 1]);
    }
    int root = dfs(1, n);

    ll TotalCost(0);
    cin >> m;
    FOR(i, 1, m) {
        int x, y, w; cin >> x >> y >> w;
        TotalCost += w;
        int u = x;
        FORD(i, K - 1, 0) if(P[u][i] > 0 && a[P[u][i]] < y)
            u = P[u][i];
        stars[u].emplace_back(x, w);
    }

    fenwicktree bit(n);
    
    function<ll(int)> solve = [&] (int root) {
        for(int v : g[root])
            dp[root] += solve(v);
        
        bit.upd(in[root], out[root], dp[root]);
        for(auto [v, w] : stars[root]) {
            maximize(dp[root], w + bit.get(in[v]));
        }
        bit.upd(in[root], out[root], -dp[root]);  
        return dp[root];
    };
    cout << TotalCost - solve(root) << '\n';
}

signed main() {
    if(fopen("test.inp","r")) {
        freopen("test.inp","r",stdin);
        freopen("test.out","w",stdout);
    }
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int ntests = 1;
    // cin >> ntests;
    while(ntests--) process();

    // cerr << "Time elapsed: " << (1.0 * clock() / CLOCKS_PER_SEC) << " s!\n";
    return 0;
}
// https://oj.uz/problem/view/JOI20_constellation3

Compilation message (stderr)

constellation3.cpp: In function 'int main()':
constellation3.cpp:137:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  137 |         freopen("test.inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
constellation3.cpp:138:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  138 |         freopen("test.out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 21 / 21
• Subtask 3: 65 / 65