結果
| 問題 | No.4 おもりと天秤 | 
| コンテスト | |
| ユーザー |  | 
| 提出日時 | 2021-12-28 11:23:05 | 
| 言語 | C++14 (gcc 13.3.0 + boost 1.87.0) | 
| 結果 | 
                                AC
                                 
                             | 
| 実行時間 | 7 ms / 5,000 ms | 
| コード長 | 2,845 bytes | 
| コンパイル時間 | 1,758 ms | 
| コンパイル使用メモリ | 172,488 KB | 
| 実行使用メモリ | 7,680 KB | 
| 最終ジャッジ日時 | 2024-10-02 01:58:10 | 
| 合計ジャッジ時間 | 2,987 ms | 
| ジャッジサーバーID (参考情報) | judge5 / judge2 | 
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| ファイルパターン | 結果 | 
|---|---|
| other | AC * 23 | 
ソースコード
#include <bits/stdc++.h>
#define REP(i,n) for (int i = 0; i < (n); ++i)
template<class T> inline bool chmin(T& a, T b) {if (a > b) {a = b;return true;}return false;}
template<class T> inline bool chmax(T& a, T b) {if (a < b) {a = b;return true;}return false;}
using namespace std;
using ll = long long;
using P = pair<int,int>;
using Pl = pair<long long,long long>;
using veci = vector<int>;
using vecl = vector<long long>;
using vecveci = vector<vector<int>>;
using vecvecl = vector<vector<long long>>;
const int MOD = 1000000007;
const double pi = acos(-1);
ll gcd(ll a, ll b) {if(b == 0) return a; else return gcd(b,a%b);}
ll lcm(ll a, ll b) {return a*b/gcd(a,b);}
template<int MOD> struct Fp {
    long long val;
    constexpr Fp(long long v = 0) noexcept : val(v % MOD) {if (val < 0) val += MOD;}
    constexpr int getmod() { return MOD; }
    constexpr Fp operator - () const noexcept {return val ? MOD - val : 0;}
    constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; }
    constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; }
    constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; }
    constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; }
    constexpr Fp& operator += (const Fp& r) noexcept {val += r.val;if (val >= MOD) val -= MOD;return *this;}
    constexpr Fp& operator -= (const Fp& r) noexcept {val -= r.val;if (val < 0) val += MOD;return *this;}
    constexpr Fp& operator *= (const Fp& r) noexcept {val = val * r.val % MOD;return *this;}
    constexpr Fp& operator /= (const Fp& r) noexcept {long long a = r.val, b = MOD, u = 1, v = 0;while (b) {long long t = a / b;a -= t * b; swap(a, b);u -= t * v; swap(u, v);}val = val * u % MOD;if (val < 0) val += MOD;return *this;}
    constexpr bool operator == (const Fp& r) const noexcept {return this->val == r.val;}
    constexpr bool operator != (const Fp& r) const noexcept {return this->val != r.val;}
    friend constexpr ostream& operator << (ostream &os, const Fp<MOD>& x) noexcept {return os << x.val;}
    friend constexpr Fp<MOD> modpow(const Fp<MOD> &a, long long n) noexcept {if (n == 0) return 1;auto t = modpow(a, n / 2);t = t * t;if (n & 1) t = t * a;return t;}
};
using mint = Fp<MOD>;
int main() {
    int N; cin >> N;
    veci W(N); REP(i,N) cin >> W[i];
    vecveci dp(110,veci(10010));
    dp[0][0] = 1;
    int S = 0;
    REP(i,N) {
        S += W[i];
        REP(j,10010) {
            if(j+W[i] < 10010) dp[i+1][j+W[i]] |= dp[i][j];
            dp[i+1][j] |= dp[i][j]; 
        }
    }
    // REP(i,N+1) {
    //     REP(j,S+1) cout << dp[i][j] << " ";
    //     cout << endl;
    // }
    if(S%2 != 0) cout << "impossible" << endl;
    else {
        if(dp[N][S/2]) cout << "possible" << endl;
        else cout << "impossible" << endl;
    } 
}
            
            
            
        