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#include<iostream>#include<algorithm>#include<chrono>#include<random>#define N 50using namespace std;int a[60],b[60];int main(){    for(int i=1;i<=20;i++)  a[i]=-1;    for(int i=21;i<=50;i++) a[i]=1;    unsigned seed=chrono::system_clock::now().time_since_epoch().count();    default_random_engine dre = default_random_engine(seed);    int cnt=0;    for(int n=1;n<=1000;n++){        copy(a+1,a+N+1,b+1);        shuffle (b+1, b+N+1,dre);        int start=0,sum=0;        while(start<=50&&sum>=0){            sum+=b[++start];        }        if(start>50) cnt++;    }    cout<<cnt<<endl;    return 0;}