Submission #1064076

#	Time	Username	Problem	Language	Result	Execution time	Memory
1064076		crafticat	A Difficult(y) Choice (BOI21_books)	C++17	10 / 100	1 ms	596 KiB

books

#include <bits/stdc++.h>

using namespace std;

#include <bits/stdc++.h>

#include <utility>
using namespace std;

using ll = __int128;
using pi = pair<ll,ll>;
using pl = pair<ll,ll>;

#define temp(T) template<class T>
temp(T) using V = vector<T>;
using vi = V<ll>;
using vl = V<ll>;
using vvi = V<vi>;
using vpi = V<pi>;
using vb = V<bool>;
using vvb = V<vb>;
vi dx = {0,1,-1,0};
vi dy = {1,0,0,-1};

#define sz(x) x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define sor(x) sort(all(x))
#define rsz resize
#define ins insert
#define pb push_back
#define eb emplace_back
#define f first
#define s second

#define lb lower_bound
#define ub upper_bound

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

using str = string;

const ll MOD = 1e9 + 7;
const ll BIG = 1e18;
const ll INF = 1e9 + 2;

temp(T) bool ckmin(T& a, const T& b) {
    return b < a ? a = b, 1 : 0; } // set a = min(a,b)
temp(T) bool ckmax(T& a, const T& b) {
    return a < b ? a = b, 1 : 0; } // set a = max(a,b)

void unsyncIO() { cin.tie(0)->sync_with_stdio(0); }
// FILE I/O
void setIn(str s) { freopen(s.c_str(),"r",stdin); }
void setOut(str s) { freopen(s.c_str(),"w",stdout); }
void setIO(str s = "") {
    unsyncIO();
    if (sz(s)) setIn(s+".in"), setOut(s+".out"); // for USACO
}

#define read(x) ll x; cin >> x

temp(T) void pr(T x) {
    cout << to_string(x);
}
temp(T) void prln(T x) {
    cout << to_string(x) << "\n";
}


ll rand(ll a, ll b) {
    return a + rand() % (b - a + 1);
}

#define gen(x,a,b) ll x = rand(a,b)

temp(T) void moveAll(V<T> &a, V<T> &b) {
    each(x,b) {
        a.pb(x);
    }
    b.clear();
}

vi genArr(ll n, ll a, ll b) {
    vi generated(n);
    F0R(i,n) {
        generated[i] = rand(a,b);
    }
    return generated;
}

vvi genTree(ll n) {
    vvi g(n + 1);
    F0R(i,n) {
        gen(p,0,i);
        g[p].pb(i + 1);
        g[i + 1].pb(p);
    }

    return g;
}

vvb readGrid(ll a, ll b) {
    vvb grid(a + 2, vb(b + 2, true));

    F0R(i, a) {
        F0R(j, b) {
            bool k; cin >> k;
            grid[i + 1][j + 1] = k;
        }
    }
    return grid;
}

int used;
map<int, ll> cash2;

long long skim(int);
__int128 skim2(int x) {
    if (cash2.count(x)) return cash2[x];
    used--;
    if (used == 0) exit(5);
    cash2[x] = skim(x);
    return cash2[x];
}

void answer(std::vector<int>);

void impossible();

ll N2;

ll lowerbound(ll a) {
    ll l = 1, r = N2; // false, false, true
    while (r > l) {
        ll mid = (r + l) / 2;
        if (skim2(mid) >= a) {
            r = mid;
        } else
            l = mid + 1;
    }
    if (skim2(l) < a) return N2 + 1;
    return l;
}

void solve(int n, int k, long long A, int usable) {
    cash2.clear();
    used = usable;
    N2 = n;
    ll next = lowerbound(A);
    V<int> down, up;
    ll sum = 0;
    ll iter = 1;

    if (next + 1 >= k) {
        FOR(i,1, k + 1) {
            up.pb(next - i);
            sum += skim2(next - i);
        }
    }
    while (sum > A * 2 && !up.empty()) {
        ll diff = -skim2(up.back()) + skim2(iter);
        sum += diff;
        up.pop_back();
        down.pb(iter++);
    }

    if (sum >= A && sum <= 2 * A) {
        down.insert(down.end(),all(up));
        answer(down);
        return;
    }

    if (!up.empty()) exit(5);
    if (next >= N2) {
        impossible();
        return;
    }
    while (sz(down) < k - 1) {
        sum += skim2(iter);
        down.pb(iter++);
    }
    if (sz(down) == k) {
        sum -= skim2(down.back());
        down.pop_back();
    }
    sum += skim2(next);
    down.pb(next);
    if (sum >= A && sum <= 2 * A) {
        answer(down);
        return;
    }
    impossible();
}

#if DEBUG
typedef long long ll;

void __attribute__((noreturn)) __attribute__((format(prllf, 1, 2))) result(const char *msg, ...)
{
    va_list args;
    va_start(args, msg);
    vfprintf(stderr, msg, args);
    fprintf(stderr, "\n");
    va_end(args);
    exit(0);
}

    ll N, K, S, sUsed;
    long long A;
    vector<long long> seq;


    void impossible() {
        result("Impossible (not checked): %d book(s) skimmed", sUsed);
        exit(0);
    }

    long long skim(int pos) {
        printf("skim2(%d): ", pos);
        if (pos < 1 || pos > N)
            result("Invalid skim2");
        printf("%lld\n", seq[pos]);
        sUsed++;
        if (sUsed > S) result("Out of books to skim2");
        return seq[pos];
    }

    void answer(vector<int> v) {
        printf("answer({");
        for (ll i = 0; i < (ll) v.size(); ++i) {
            printf("%d", v[i]);
            if (i + 1 != (ll) v.size()) printf(", ");
        }
        printf("})\n");

        if ((ll) v.size() != K) result("Invalid answer");
        ll sum = 0;
        for (auto x: v) {
            if (x < 1 || x > N) result("Invalid answer");
            sum += seq[x];
        }
        if (sum < A || 2 * A < sum) result("Wrong answer");

        result("Correct: %d book(s) skimmed", sUsed);
        exit(0);
    }

    int main() {
        if (scanf("%d %d %lld %d", &N, &K, &A, &S) != 4)
            result("Invalid input");

        seq.resize(N + 1);
        for (ll i = 1; i <= N; ++i) {
            if (scanf("%lld", &(seq[i])) != 1) result("Invalid input");
            if (i > 1 && seq[i] <= seq[i - 1]) result("Invalid input");
        }

        solve(N, K, A, S);

        result("No answer");
    }

#endif

Compilation message (stderr)

books.cpp: In function 'void solve(int, int, long long int, int)':
books.cpp:184:21: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  184 |     while (sz(down) < k - 1) {
      |                     ^
books.cpp:188:18: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  188 |     if (sz(down) == k) {
      |                  ^
books.cpp: In function 'void setIn(str)':
books.cpp:59:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 | void setIn(str s) { freopen(s.c_str(),"r",stdin); }
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
books.cpp: In function 'void setOut(str)':
books.cpp:60:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 | void setOut(str s) { freopen(s.c_str(),"w",stdout); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 15
• Subtask 3: 10 / 10
• Subtask 4: 0 / 15
• Subtask 5: 0 / 15
• Subtask 6: 0 / 20
• Subtask 7: 0 / 20