Submission #16314461

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Source Code Expand

// dfmt off
T lread(T=long)(){return readln.chomp.to!T;}T[] lreads(T=long)(long n){return iota(n).map!((_)=>lread!T).array;}
T[] aryread(T=long)(){return readln.split.to!(T[]);}void arywrite(T)(T a){a.map!text.join(' ').writeln;}
void scan(L...)(ref L A){auto l=readln.split;foreach(i,T;L){A[i]=l[i].to!T;}}alias sread=()=>readln.chomp();
void dprint(L...)(lazy L A){debug{auto l=new string[](L.length);static foreach(i,a;A)l[i]=a.text;arywrite(l);}}
alias PQueue(T,alias l="b<a")=BinaryHeap!(Array!T,l);import std, core.bitop;
// dfmt on
immutable long MOD = 1000000007;
void main()
{
    auto input = stdin.byLine.map!split.joiner;

    long N;
    N = input.front.to!long;
    input.popFront;

    long[] A = new long[](cast(size_t)(N));
    foreach (i; 0 .. cast(size_t)(N))
    {
        A[i] = input.front.to!long;
        input.popFront;
    }

    solve(N, A);
}

void solve(long N, long[] A)
{
    long ans;
    long s = A.sum();
    foreach (a; A)
    {
        s -= a;
        ans += (s % MOD) * a;
        ans %= MOD;
    }
    writeln(ans);
}

Submission Info

Judge Result