Submission #1027836

#	Time	Username	Problem	Language	Result	Execution time	Memory
1027836		caterpillow	Snail (NOI18_snail)	C++17	100 / 100	2 ms	604 KiB

snail

#include <bits/stdc++.h>

using namespace std;

using db = long double;
using ll = long long;
using pl = pair<ll, ll>;
using pi = pair<int, int>;
#define vt vector
#define f first
#define s second
#define pb push_back
#define all(x) x.begin(), x.end() 
#define size(x) ((int) (x).size())
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define ROF(i, a, b) for (int i = (b) - 1; i >= (a); i--)
#define F0R(i, b) FOR (i, 0, b)
#define endl '\n'
const ll INF = 1e18;
const int inf = 1e9;

template<typename Tuple, size_t... Is>
void print_tuple(const Tuple& t, index_sequence<Is...>) {
    ((cerr << (Is == 0 ? "{" : ", ") << get<Is>(t)), ...);
    cerr << "}";
}

template<typename... Args>
ostream& operator<<(ostream& os, const tuple<Args...>& t) {
    print_tuple(t, index_sequence_for<Args...>{});
    return os;
}

ostream& operator<<(ostream& os, string& s) {
    for (char c : s) os << c; 
    return os;
}

template<template<typename> class Container, typename T>
ostream& operator<<(ostream& os, Container<T> o) {
    os << "{"; 
    int g = size(o); 
    for (auto i : o) os << i << ((--g) == 0 ? "" : ", "); 
    os << "}";
    return os;
}

template<typename T, typename V>
ostream& operator<<(ostream& os, const pair<T, V> p) {
    os << "{" << p.f << ", " << p.s << "}";
    return os;
}

template <typename T, typename... V>
void printer(const char *names, T &&head, V &&...tail) {
    int i = 0;
    while (names[i] != '\0' && names[i] != ',') i++;
    constexpr bool is_str = is_same_v<decay_t<T>, const char*>;
    if constexpr (is_str) cerr << head; // ignore directly passed strings
    else cerr.write(names, i) << " = " << head; 
    if constexpr (sizeof...(tail)) cerr << (is_str ? "" : ","), printer(names + i + 1, tail...);
    else cerr << endl;
}

#ifdef LOCAL
#define dbg(...) std::cerr << __LINE__ << ": ", printer(#__VA_ARGS__, __VA_ARGS__)
#else
#define dbg(x...)
#define cerr if (0) std::cerr
#endif

/*

if you ever touch the ground, you will "restart" from the min point in your pfx sum

*/

main() {
    cin.tie(0)->sync_with_stdio(0);
    
    ll h, n; cin >> h >> n;
    vt<ll> a(n), pfx(n);
    F0R (i, n) cin >> a[i];
    F0R (i, n) pfx[i] = a[i] + (i ? pfx[i - 1] : 0);

    // check if you reach your goal on day 1 and 2
    ll y = 0, day = 0;
    F0R (_, 2) {
        F0R (i, n) {
            y = max(0ll, y + a[i]);
            if (y >= h) {
                cout << day << " " << i << endl;
                return 0;
            }
        }
        day++;
    }

    ll mn = *min_element(all(pfx));
    ll mx = *max_element(all(pfx));

    if (y + mn <= 0) {
        // impossible
        cout << "-1 -1\n";
        return 0;
    }

    // find first day where you start at a level >= h - mx
    ll jump = (h - mx - y + pfx.back() - 1) / pfx.back(); // distance to cover / distance covered each day (rounded up)
    y += jump * pfx.back();
    day += jump;
    dbg(y, day);
    F0R (i, n) {
        y += a[i];
        if (y >= h) {
            cout << day << " " << i << endl;
            return 0;
        }
    }
    assert(0);
}

Compilation message (stderr)

snail.cpp:78:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   78 | main() {
      | ^~~~

• Subtask 1: 11 / 11
• Subtask 2: 9 / 9
• Subtask 3: 25 / 25
• Subtask 4: 17 / 17
• Subtask 5: 38 / 38