luogu_P5020 货币系统

什么玄学数组大小。。。开了10背才过

#include<iostream>
#include<cstdio>

#define ri register int
#define u int

namespace opt {

    inline u in() {
        u x(0),f(1);
        char s(getchar());
        while(s<'0'||s>'9') {
            if(s=='-') f=-1;
            s=getchar();
        }
        while(s>='0'&&s<='9') {
            x=(x<<1)+(x<<3)+s-'0';
            s=getchar();
        }
        return x*f;
    }

}

using opt::in;

#include<algorithm>
#include<cstring>

#define NN 250005

namespace mainstay {

    u kin[NN],a[NN];

    inline void solve() {
        u T(in());
        while(T--) {
            std::memset(kin,0,sizeof(kin));
            std::memset(a,0,sizeof(a));
            u N(in());
            for(ri i(1);i<=N;++i){
                a[i]=in();
                kin[a[i]]=2;
            }
            std::sort(a+1,a+N+1);
            for(ri i(1);i<=a[N];++i){
                if(kin[i]){
                    for(ri j(1);j<=N;++j){
                        kin[i+a[j]]=1;
                    }
                }
            }
            u ans(0);
            for(ri i(1);i<=N;++i) ans+=(kin[a[i]]==2);
            std::cout<<ans<<std::endl;
        }
    }

}

int main() {

    //freopen("x.txt","r",stdin);
    std::ios::sync_with_stdio(false);
    mainstay::solve();

}

 

来源：https://www.cnblogs.com/ling-zhi/p/11787369.html