#439734 (C++17(clang)) No.1007 コイン集め

• 問題: No.1007 コイン集め
• ユーザー: mai
• 提出日時: 2020-03-06 22:25:43
• 言語: C++17(clang) (17.0.6 + boost 1.83.0)
• 結果: AC
• 実行時間: 6 ms / 1,500 ms
• コード長: 5,624 bytes
• コンパイル時間: 2,118 ms
• コンパイル使用メモリ: 162,756 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-05-07 20:40:44
• 合計ジャッジ時間: 3,136 ms
• ジャッジサーバーID （参考情報）: judge4 / judge1

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	1 ms; 5,248 KB
testcase_01	AC	2 ms; 5,376 KB
testcase_02	AC	1 ms; 5,376 KB
testcase_03	AC	1 ms; 5,376 KB
testcase_04	AC	1 ms; 5,376 KB
testcase_05	AC	1 ms; 5,376 KB
testcase_06	AC	1 ms; 5,376 KB
testcase_07	AC	2 ms; 5,376 KB
testcase_08	AC	1 ms; 5,376 KB
testcase_09	AC	1 ms; 5,376 KB
testcase_10	AC	2 ms; 5,376 KB
testcase_11	AC	2 ms; 5,376 KB
testcase_12	AC	6 ms; 5,376 KB
testcase_13	AC	5 ms; 5,376 KB
testcase_14	AC	6 ms; 5,376 KB
testcase_15	AC	3 ms; 5,376 KB
testcase_16	AC	3 ms; 5,376 KB
testcase_17	AC	3 ms; 5,376 KB
testcase_18	AC	5 ms; 5,376 KB
testcase_19	AC	5 ms; 5,376 KB
testcase_20	AC	5 ms; 5,376 KB
testcase_21	AC	4 ms; 5,376 KB

ソースコード

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

using namespace std;
using ll = long long int;

#define debugos cout
#define debug(v) {printf("L%d %s > ",__LINE__,#v);debugos<<(v)<<endl;}
#define debugv(v) {printf("L%d %s > ",__LINE__,#v);for(auto e:(v)){debugos<<e<<" ";}debugos<<endl;}
#define debuga(m,w) {printf("L%d %s > ",__LINE__,#m);for(int x=0;x<(w);x++){debugos<<(m)[x]<<" ";}debugos<<endl;}
#define debugaa(m,h,w) {printf("L%d %s >\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){debugos<<(m)[y][x]<<" ";}debugos<<endl;}}
#define all(v) (v).begin(),(v).end()
#define repeat(cnt,l) for(auto cnt=decltype(l)();(cnt)<(l);++(cnt))
#define rrepeat(cnt,l) for(auto cnt=(l)-1;0<=(cnt);--(cnt))
#define iterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);++(cnt))
#define diterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);--(cnt))
#define lambda(type,fun) [&]type{return(fun);}
#define assert_eq(ex,ac) if (!((ex) == (ac))) {cerr << "assertion fault(==): " #ex " = " << ex << ", " #ac << " = " << ac << endl; abort();}
const ll MD = 1000000007ll; const long double PI = 3.1415926535897932384626433832795L;
template<typename T1, typename T2> inline ostream& operator <<(ostream& o, const pair<T1, T2> p) { o << '(' << p.first << ':' << p.second << ')'; return o; }
template<typename Vec> inline ostream& _ostream_vecprint(ostream& os, const Vec& a) {
    os << '['; for (const auto& e : a) os << ' ' << e << ' '; os << ']'; return os;
}
template<typename T> inline ostream& operator<<(ostream & o, const vector<T> & v) { return _ostream_vecprint(o, v); }
template<typename T, size_t S> inline ostream& operator<<(ostream & o, const array<T, S> & v) { return _ostream_vecprint(o, v); }
template<typename T> inline T& chmax(T & to, const T & val) { return to = max(to, val); }
template<typename T> inline T& chmin(T & to, const T & val) { return to = min(to, val); }
void bye(string s, int code = 0) { cout << s << endl; exit(code); }
mt19937_64 randdev(8901016);
template<typename T, typename Random = decltype(randdev), typename enable_if<is_integral<T>::value>::type* = nullptr>
inline T rand(T l, T h, Random & rand = randdev) { return uniform_int_distribution<T>(l, h)(rand); }
template<typename T, typename Random = decltype(randdev), typename enable_if<is_floating_point<T>::value>::type* = nullptr>
inline T rand(T l, T h, Random & rand = randdev) { return uniform_real_distribution<T>(l, h)(rand); }

#if defined(_WIN32) || defined(_WIN64)
#define getc_x _getc_nolock
#define putc_x _putc_nolock
#elif defined(__GNUC__)
#define getc_x getc_unlocked
#define putc_x putc_unlocked
#else
#define getc_x getc
#define putc_x putc
#endif
#define isvisiblechar(c) (0x21<=(c)&&(c)<=0x7E)
class MaiScanner {
    FILE* fp_;
public:
    inline MaiScanner(FILE* fp) :fp_(fp) {}
    template<typename T> void input_integer(T& var) noexcept {
        var = 0; T sign = 1;
        int cc = getc_x(fp_);
        for (; cc < '0' || '9' < cc; cc = getc_x(fp_))
            if (cc == '-') sign = -1;
        for (; '0' <= cc && cc <= '9'; cc = getc_x(fp_))
            var = (var << 3) + (var << 1) + cc - '0';
        var = var * sign;
    }
    inline int c() noexcept { return getc_x(fp_); }
    inline MaiScanner& operator>>(int& var) noexcept { input_integer<int>(var); return *this; }
    inline MaiScanner& operator>>(long long& var) noexcept { input_integer<long long>(var); return *this; }
    inline MaiScanner& operator>>(string & var) {
        int cc = getc_x(fp_);
        for (; !isvisiblechar(cc); cc = getc_x(fp_));
        for (; isvisiblechar(cc); cc = getc_x(fp_))
            var.push_back(cc);
        return *this;
    }
    template<typename IT> inline void in(IT begin, IT end) { for (auto it = begin; it != end; ++it) * this >> *it; }
};
class MaiPrinter {
    FILE* fp_;
public:
    inline MaiPrinter(FILE* fp) :fp_(fp) {}
    template<typename T>
    void output_integer(T var) noexcept {
        if (var == 0) { putc_x('0', fp_); return; }
        if (var < 0)
            putc_x('-', fp_),
            var = -var;
        char stack[32]; int stack_p = 0;
        while (var)
            stack[stack_p++] = '0' + (var % 10),
            var /= 10;
        while (stack_p)
            putc_x(stack[--stack_p], fp_);
    }
    inline MaiPrinter& operator<<(char c) noexcept { putc_x(c, fp_); return *this; }
    inline MaiPrinter& operator<<(int var) noexcept { output_integer<int>(var); return *this; }
    inline MaiPrinter& operator<<(long long var) noexcept { output_integer<long long>(var); return *this; }
    inline MaiPrinter& operator<<(char* str_p) noexcept { while (*str_p) putc_x(*(str_p++), fp_); return *this; }
    inline MaiPrinter& operator<<(const string& str) {
        const char* p = str.c_str();
        const char* l = p + str.size();
        while (p < l) putc_x(*p++, fp_);
        return *this;
    }
    template<typename IT> void join(IT begin, IT end, char sep = ' ') { for (bool b = 0; begin != end; ++begin, b = 1) b ? *this << sep << *begin : *this << *begin; }
};
MaiScanner scanner(stdin);
MaiPrinter printer(stdout);


//

int N, K;
ll A[200010];

// 1枚：折返し
// 2枚以上: ふりーだむ

//


int main() {
  
  scanner >> N >> K; --K;
  scanner.in(A, A+N);
  
  ll left = 0, right = 0;
  for (int x = K-1; 0 <= x; --x) {
    left += A[x];
    if (A[x] <= 1)
      break;
  }
  for (int x = K+1; x < N; ++x) {
    right += A[x];
    if (A[x] <= 1)
      break;
  }
  
  if (A[K] == 0) {
    cout << 0 << endl;
  }
  else if (A[K] == 1) {
    cout << max(left, right)+1 << endl;
  }
  else {
    cout << left + right + A[K] << endl;
  }
  
  return 0;
}