LeAf146's blog

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signed main(){
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    int n,m;cin>>n>>m;
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    int minn=(n+1)/2,maxx=n;
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    int ans=-1;
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    for(int i=minn;i<=maxx;i++){
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        if(i%m==0){
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            ans=i;
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            break;
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        }
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    }
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    cout<<ans<<endl;
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    return 0;
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}

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int qmi(int a,int b){
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    int ans=1;
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    while(b){
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        if(b&1)ans=ans*a;
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        a=a*a;
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        b>>=1;
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    }
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    return ans;
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}
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int C(int A,int a){
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    if(a>A)return 0;
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    int ans=1;
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    for(int i=1,j=A;i<=a;i++,j--){
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        ans=ans*j;
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        ans=ans/i;
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    }
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    return ans;
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}
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signed main(){
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    string s;cin>>s;
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    int cnt[2]={0};
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    for(int i=0;i<s.size();i++){
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        if(s[i]=='+')cnt[1]++;
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        else cnt[0]++;
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    }
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    cin>>s;
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    for(int i=0;i<s.size();i++){
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        if(s[i]=='+')cnt[1]--;
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        else if(s[i]=='-')cnt[0]--;
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    }
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    if(cnt[0]<0||cnt[1]<0)cout<<"0.000000000000\n";
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    else{
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        double d=1;
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        for(int i=0;i<cnt[0]+cnt[1];i++)d/=2;
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        cout<<fixed<<setprecision(12)<<C(cnt[0]+cnt[1],cnt[0])*d<<endl;
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    }
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    return 0;
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}

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const int mod=1e9+7;
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signed main(){
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    int a,b;cin>>a>>b;
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    a=(((1+a)*a/2)%mod*b%mod+a)%mod;
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    cout<<((b-1)*b/2)%mod*a%mod<<endl;
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    return 0;
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}