运行 ID: 118424

Main.cc: In function ‘int main()’:
Main.cc:18:4: error: ‘ans’ was not declared in this scope
    ans+=(k-j-1)*a[j]-tmp;
    ^~~
Main.cc:18:4: note: suggested alternative: ‘abs’
    ans+=(k-j-1)*a[j]-tmp;
    ^~~
    abs