Submission #554780

#	Time	Username	Problem	Language	Result	Execution time	Memory
554780		SmolBrain	Growing Trees (BOI11_grow)	C++17	100 / 100	127 ms	1580 KiB

grow

// Om Namah Shivaya
// GM in 95 days

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define endl '\n'
#define pb push_back
#define conts continue
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define ff first
#define ss second
#define ceil2(x,y) ((x+y-1) / (y))
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#ifndef ONLINE_JUDGE
#define debug(x) cout << #x <<" = "; print(x); cout << endl
#else
#define debug(x)
#endif

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

bool iseven(ll n) {if ((n & 1) == 0) return true; return false;}

void print(ll t) {cout << t;}
void print(int t) {cout << t;}
void print(string t) {cout << t;}
void print(char t) {cout << t;}
void print(double t) {cout << t;}
void print(ld t) {cout << t;}

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(pair <T, V> p) {cout << "{"; print(p.ff); cout << ","; print(p.ss); cout << "}";}
template <class T> void print(vector <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(set <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(multiset <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T, class V> void print(map <T, V> v) {cout << "[ "; for (auto i : v) {print(i); cout << " ";} cout << "]";}
template<typename T> void amin(T &a, T b) { a = min(a, b); }
template<typename T> void amax(T &a, T b) { a = max(a, b); }

void usaco(string filename) {
    freopen((filename + ".in").c_str(), "r", stdin);
    freopen((filename + ".out").c_str(), "w", stdout);
}

const int MOD = 1e9 + 7;
const int maxn = 1e5 + 5;
const int inf1 = 1e9 + 5;
const ll inf2 = ll(1e18) + 5;

template<typename T>
struct fenwick {
    int siz;
    vector<T> tree;

    fenwick(int n) {
        siz = n;
        tree = vector<T>(n + 1);
    }

    int lsb(int x) {
        return x & -x;
    }

    void build(vector<T> &a, int n) {
        for (int i = 1; i <= n; ++i) {
            int par = i + lsb(i);
            tree[i] += a[i];

            if (par <= siz) {
                tree[par] += tree[i];
            }
        }
    }

    void pupd(int i, T v) {
        i++;
        while (i <= siz) {
            tree[i] += v;
            i += lsb(i);
        }
    }

    T sum(int i) {
        T res = 0;

        while (i) {
            res += tree[i];
            i -= lsb(i);
        }

        return res;
    }

    T query(int l, int r) {
        l++, r++;
        T res = sum(r) - sum(l - 1);
        return res;
    }
};

void solve(int test_case)
{
    // references:
    // https://oj.uz/submission/549945
    // https://csacademy.com/contest/round-41/task/candles/solution/
    // https://csacademy.com/submission/371177/

    int n, m; cin >> n >> m;
    vector<int> a(n);
    rep(i, n) cin >> a[i];

    sort(all(a));

    fenwick<int> fenw(n + 5);
    rep(i, n) {
        fenw.pupd(i, a[i]);
        fenw.pupd(i + 1, -a[i]);
    }

    auto first = [&](int x) {
        // returns first occurrence of x in the segtree
        int l = 0, r = n - 1;
        int pos = -1;

        while (l <= r) {
            int mid = (l + r) / 2;
            int res = fenw.query(0, mid);

            if (res >= x) {
                pos = mid;
                r = mid - 1;
            }
            else {
                l = mid + 1;
            }
        }

        return pos;
    };

    auto last = [&](int x) {
        // returns last occurrence of x in the segtree
        int l = 0, r = n - 1;
        int pos = -1;

        while (l <= r) {
            int mid = (l + r) / 2;
            int res = fenw.query(0, mid);

            if (res > x) {
                r = mid - 1;
            }
            else {
                pos = mid;
                l = mid + 1;
            }
        }

        return pos;
    };

    auto upper_bound = [&](int x) {
        // returns first position where value > x
        int l = 0, r = n - 1;
        int pos = n;

        while (l <= r) {
            int mid = (l + r) / 2;
            int res = fenw.query(0, mid);

            if (res > x) {
                pos = mid;
                r = mid - 1;
            }
            else {
                l = mid + 1;
            }
        }

        return pos;
    };

    auto lower_bound = [&](int x) {
        // returns first position where value >= x
        int l = 0, r = n - 1;
        int pos = n;

        while (l <= r) {
            int mid = (l + r) / 2;
            int res = fenw.query(0, mid);

            if (res >= x) {
                pos = mid;
                r = mid - 1;
            }
            else {
                l = mid + 1;
            }
        }

        return pos;
    };

    while (m--) {
        char ch; cin >> ch;
        if (ch == 'F') {
            int c, h; cin >> c >> h;

            int l = lower_bound(h);
            int r = min(l + c - 1, n - 1);

            int mx = fenw.query(0, r);
            int firstpos = first(mx);
            int lastpos = last(mx);

            if (l <= firstpos - 1) {
                fenw.pupd(l, 1);
                fenw.pupd((firstpos - 1) + 1, -1);
            }

            int len1 = r - l + 1;
            int len2 = max((firstpos - 1) - l + 1, 0);
            int left = len1 - len2;

            if (lastpos - left + 1 <= lastpos) {
                fenw.pupd(lastpos - left + 1, 1);
                fenw.pupd(lastpos + 1, -1);
            }
        }
        else {
            int l, r; cin >> l >> r;
            int ans = upper_bound(r) - lower_bound(l);
            cout << ans << endl;
        }
    }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;
    rep1(i, t) {
        solve(i);
    }

    return 0;
}

Compilation message (stderr)

grow.cpp: In function 'void usaco(std::string)':
grow.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |     freopen((filename + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
grow.cpp:65:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |     freopen((filename + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10