String query with binary indexed tree

Question

I want to range query a string using Fenwick tree. But something is going wrong with my code. Concatenation is giving error Eror is:[Error] no match for 'operator+=' (operand types are 'std::vector >' and 'std::string {aka std::basic_string}') Given a string s, I want to store the string in this fenwick tree. e.g. s=abcdef, on BIT it should like(top-bottom) a ab-c abcd-e abcd-ef Tree Structure

vector<string> BIT[100005];
    int n;
    void BI(int x,string c)
    {
        for(;x<=n;x+=x&-x)  
        {
            BIT[x]+=c;
        }

    }

    int main()
    {
        cin>>n;
        string s;
        for(int i=1;i<=n;i++)
        {   cin>>s;
            BI(i,s);
        }

    }

It's not clear what data this is processing, nor what the output should be. — tadman, Jul 10 '17 at 14:27
e.g. s=abcdef, on BIT it should like(up-bottom) a ab-c abcd-e abcd-ef — nRT, Jul 10 '17 at 14:28
Isn't `std::vector y[n]` a C-style array of vectors? Why not a `std::vector>`? — tadman, Jul 10 '17 at 14:28
Don't understand your tree formatting. You mean "top to bottom," right? But what are the spaces and what are the dashes? Can you write in heap format, _e.g._ a, ab, c, abcd, null, null, e, etc. — Andrew Cheong, Jul 10 '17 at 14:35
spaces is between two consecutive depths and dashes meant parent-child — nRT, Jul 10 '17 at 14:38
`But something is going wrong with my code.` What? Where? Don't just post _'it doesn't work'_ without explaining what specifically is wrong. — underscore_d, Jul 10 '17 at 14:46

score 1 · Accepted Answer · answered Jul 10 '17 at 14:50

This

vector<string> BIT[100005];

and this

BIT[x]+=c;

don't go together. You have an array of vectors of strings (2-dimensional matrix, basically). And you are trying to add string c to a vector at BIT[x]. Your compile errors should be telling you this.

You probably did not mean to make an array of vector of strings. To make a vector of strings with size 100005, do this:

vector<string> BIT(100005);

i.e. parentheses, not square brackets.

String query with binary indexed tree

1 Answers1