#391061 (C++14) No.910 素数部分列

• 問題: No.910 素数部分列
• ユーザー: knshnb
• 提出日時: 2019-10-18 22:06:48
• 言語: C++14 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 7 ms / 1,000 ms
• コード長: 4,272 bytes
• コンパイル時間: 2,767 ms
• コンパイル使用メモリ: 195,688 KB
• 実行使用メモリ: 5,832 KB
• 最終ジャッジ日時: 2024-06-25 21:31:23
• 合計ジャッジ時間: 4,300 ms
• ジャッジサーバーID （参考情報）: judge5 / judge1

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	2 ms; 5,248 KB
testcase_01	AC	2 ms; 5,376 KB
testcase_02	AC	2 ms; 5,376 KB
testcase_03	AC	2 ms; 5,376 KB
testcase_04	AC	2 ms; 5,376 KB
testcase_05	AC	2 ms; 5,376 KB
testcase_06	AC	2 ms; 5,376 KB
testcase_07	AC	2 ms; 5,376 KB
testcase_08	AC	2 ms; 5,376 KB
testcase_09	AC	2 ms; 5,376 KB
testcase_10	AC	2 ms; 5,376 KB
testcase_11	AC	2 ms; 5,376 KB
testcase_12	AC	2 ms; 5,376 KB
testcase_13	AC	2 ms; 5,376 KB
testcase_14	AC	2 ms; 5,376 KB
testcase_15	AC	2 ms; 5,376 KB
testcase_16	AC	2 ms; 5,376 KB
testcase_17	AC	2 ms; 5,376 KB
testcase_18	AC	2 ms; 5,376 KB
testcase_19	AC	2 ms; 5,376 KB
testcase_20	AC	2 ms; 5,376 KB
testcase_21	AC	2 ms; 5,376 KB
testcase_22	AC	2 ms; 5,376 KB
testcase_23	AC	5 ms; 5,376 KB
testcase_24	AC	5 ms; 5,376 KB
testcase_25	AC	5 ms; 5,376 KB
testcase_26	AC	5 ms; 5,376 KB
testcase_27	AC	5 ms; 5,376 KB
testcase_28	AC	5 ms; 5,376 KB
testcase_29	AC	5 ms; 5,376 KB
testcase_30	AC	4 ms; 5,376 KB
testcase_31	AC	5 ms; 5,376 KB
testcase_32	AC	5 ms; 5,376 KB
testcase_33	AC	5 ms; 5,376 KB
testcase_34	AC	5 ms; 5,376 KB
testcase_35	AC	5 ms; 5,376 KB
testcase_36	AC	5 ms; 5,376 KB
testcase_37	AC	5 ms; 5,376 KB
testcase_38	AC	6 ms; 5,376 KB
testcase_39	AC	6 ms; 5,376 KB
testcase_40	AC	5 ms; 5,376 KB
testcase_41	AC	5 ms; 5,376 KB
testcase_42	AC	7 ms; 5,376 KB
testcase_43	AC	6 ms; 5,376 KB
testcase_44	AC	6 ms; 5,376 KB
testcase_45	AC	6 ms; 5,376 KB
testcase_46	AC	5 ms; 5,376 KB
testcase_47	AC	6 ms; 5,376 KB
testcase_48	AC	6 ms; 5,832 KB
testcase_49	AC	6 ms; 5,832 KB
testcase_50	AC	6 ms; 5,832 KB
testcase_51	AC	4 ms; 5,376 KB
testcase_52	AC	4 ms; 5,376 KB

ソースコード

#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 treap = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
using Int = long long;
#define REP(i, n) for (long long i = 0, max_i = (n); i < max_i; i++)
#define REPI(i, a, b) for (long long i = (a), max_i = (b); i < max_i; i++)
#define ALL(obj) begin(obj), end(obj)
#define RALL(obj) rbegin(obj), rend(obj)
#define fi first
#define se second
using ii = pair<Int, Int>;
vector<ii> dirs = {
    {1, 0}, {0, 1}, {-1, 0}, {0, -1},  // 4方向
    {1, 1}, {-1, 1}, {-1, -1}, {1, -1},  // 斜め
    {0, 0},  // 自身
};
Int get_msb(long long x) {
    assert(x != 0);
    return 63 - __builtin_clzll(x);
}
Int get_lsb(long long x) {
    assert(x != 0);
    return __builtin_ctzll(x);
}
template <class T> inline bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } return false; }
template <class T> inline bool chmin(T& a, const T& b) { if (a > b) { a = b; return true; } return false; }
template <class T, class S> vector<T> make_vec(size_t n, S x) { return vector<T>(n, x); }
template <class T, class... Ts> auto make_vec(size_t n, Ts... ts) { return vector<decltype(make_vec<T>(ts...))>(n, make_vec<T>(ts...)); }

// debug
template <class T> ostream& operator<<(ostream& s, const vector<T>& d) { REP (i, d.size()) s << d[i] << (i == d.size() - 1 ? "" : " "); return s; }
template <class T> ostream& operator<<(ostream& s, const vector<vector<T>>& d) { REP (i, d.size()) s << d[i] << (i == d.size() - 1 ? "" : "\n"); return s; }
template <class T, class S> ostream& operator<<(ostream& s, const pair<T, S>& p) { s << "{" << p.first << ", " << p.second << "}"; return s; }
template <class T> ostream& operator<<(ostream& s, const set<T> m) { for (auto it = m.begin(); it != m.end(); it++) { s << *it << (next(it) == m.end() ? "" : "\n"); } return s; }
template <class T> ostream& operator<<(ostream& s, const multiset<T> m) { for (auto it = m.begin(); it != m.end(); it++) { s << *it << (next(it) == m.end() ? "" : "\n"); } return s; }
template <class T, class S> ostream& operator<<(ostream& s, const map<T, S> m) { for (auto it = m.begin(); it != m.end(); it++) { s << *it << (next(it) == m.end() ? "" : "\n"); } return s; }
template <class T, class S> ostream& operator<<(ostream& s, const unordered_map<T, S> m) { for (auto it = m.begin(); it != m.end(); it++) { s << *it << (next(it) == m.end() ? "" : "\n"); } return s; }
#ifdef _MY_DEBUG
    #define dump(...) cerr << "/* " << #__VA_ARGS__ << " :[" << __LINE__ << ":" << __FUNCTION__ << "]" << endl, dump_func(__VA_ARGS__), cerr << "*/\n\n";
#else
    #define dump(...)
    #define endl "\n"
#endif
void dump_func() { cerr << endl; }
template <class Head, class... Tail> void dump_func(Head&& h, Tail&&... t) { cerr << h << (sizeof...(Tail) == 0 ? "" : ", "), dump_func(forward<Tail>(t)...); }

struct Fast { Fast() { cin.tie(nullptr); ios::sync_with_stdio(false); } } fast;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
constexpr Int MOD = 1000000007;
// *************** TEMPLATE END *************** 

signed main() {
    Int n; cin >> n;
    string s; cin >> s;
    Int ans = 0;
    vector<Int> one, nine;
    vector<bool> used(n);
    REP (i, n) {
        char c = s[i];
        if (c == '3' || c == '5' || c == '7') {
            ans++;
            used[i] = true;
        } else if (c == '9') {
            if (one.size() > 0) {
                used[one.back()] = true;
                used[i] = true;
                one.pop_back();
                ans++;
            } else {
                nine.push_back(i);
            }
        } else if (c == '1') {
            one.push_back(i);
        } else assert(0);
    }
    one.clear();
    nine.clear();
    REP (i, n) {
        if (used[i]) continue;
        char c = s[i];
        if (c == '9') {
            nine.push_back(9);
        } else if (c == '1') {
            if (nine.size() >= 2) {
                nine.pop_back();
                nine.pop_back();
                ans++;
            } else {
                one.push_back(i);
            }
        }
    }
    ans += one.size() / 2;
    cout << ans << endl;
}