제출 #1303119

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1303119		the_commando_x	PIN (CEOI10_pin)	C++17	100 / 100	22 ms	4328 KiB

pin

// #pragma GCC optimize("O3")
#include <bits/stdc++.h>

using namespace std;

using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;

using pii = pair<int, int>;
using vii = vector<pii>;
using vvii = vector<vii>;

using l = long long;
using vl = vector<l>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;

using pll = pair<l, l>;
using vll = vector<pll>;
using vvll = vector<vll>;

using d = double;
using vd = vector<d>;
using vvd = vector<vd>;
using vvvd = vector<vvd>;

using ld = long double;
using vld = vector<ld>;
using vvld = vector<vld>;
using vvvld = vector<vvld>;

using vb = vector<bool>;
using vvb = vector<vb>;
using pbb = pair<bool, bool>;
using vbb = vector<pbb>;

#define ff first
#define ss second

#define pb push_back
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) (int)(x).size()

void setIO(string name = "")
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if (!name.empty())
    {
        (void)freopen((name + ".in").c_str(), "r", stdin);
        (void)freopen((name + ".out").c_str(), "w", stdout);
    }
}

const ld pi = 3.14159265358979323846;

const l LINF = 1e18;
const l INF = 1e9;

const l MOD = 1e9 + 7;
// const l MOD = 998244353;

const l MAXN = 2e5 + 5;

l hashsubset(const string &s, int mask)
{
    l res = 0;
    for (int bit = 0; bit < 4; ++bit)
        if (mask & (1 << bit))
        {

            char c = s[bit];
            res *= 37;
            if (isdigit(c))
                res += c - '0' + 1;
            else
                res += c - 'a' + 10 + 1;
        }

    return res;
}

void solve()
{
    l N, D;
    cin >> N >> D;

    vector<string> a(N);
    for (auto &s : a)
        cin >> s;

    vl cnt(16, 0); // cnt[mask]

    for (int mask = 0; mask < 16; ++mask)
    {
        unordered_map<l, l> mp; // {key,cnt}
        mp.reserve(N * 2);

        for (int i = 0; i < N; ++i)
        {
            l key = hashsubset(a[i], mask);
            ++mp[key];
        }

        l sum = 0;
        for (auto &[_, freq] : mp)
            sum += ((freq - 1) * freq) / 2;

        cnt[mask] = sum;
    }

    vl totCnt(5, 0);
    for (int mask = 0; mask < 16; ++mask)
        totCnt[__builtin_popcount(mask)] += cnt[mask];

    vl ans(5, 0);
    ans[4] = totCnt[4];
    ans[3] = totCnt[3] - 4 * ans[4];
    ans[2] = totCnt[2] - 3 * ans[3] - 6 * ans[4];
    ans[1] = totCnt[1] - 2 * ans[2] - 3 * ans[3] - 4 * ans[4];
    ans[0] = (N * (N - 1) / 2) - (ans[1] + ans[2] + ans[3] + ans[4]);

    cout << ans[4 - D];
}

int main()
{
    setIO("");

#ifndef ONLINE_JUDGE
    // setIO("filename");
#endif

    int t = 1;
    // cin >> t;
    while (t--)
        solve();

    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

pin.cpp: In function 'void setIO(std::string)':
pin.cpp:53:22: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   53 |         (void)freopen((name + ".in").c_str(), "r", stdin);
      |               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pin.cpp:54:22: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   54 |         (void)freopen((name + ".out").c_str(), "w", stdout);
      |               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100