c++ unhandled exception. what's going on?

Question

i'm trying to make a Shannon code maker from input text, and i have some troubles...

so, there is some simple shit-code

int main()
{
    string x="this is very big text.";
    int temp;
    int N = x.length();
    int *mass = new int [N];

then counting symbols in text;

then counting symbols that used from ASCII table;

creating new 2 massives with symbols and counters of symbol, but their dimention is quite smaller;

delete old char massive by delete mass;

sort 'em by counters and counting their cumulative probability;

double * cumulative = new double (k);
            double temp=int_mass[0];
            cumulative[0]=0;
            for (int i=1; i<k; i++)
        {
            temp=int_mass[i-1];
            cumulative[i]=cumulative[i-1]+temp/N;
        }    

cout'ing all 3 massives

double a,b,n;
n=N;
for (int i=0; i<k; i++)
{
    b=int_mass[i];
    b/=n;
    cout<<char_mass[i]<<" ";
    cout<<b<<" ";                       //**__**__**
    cout<<cumulative[i]<<endl;
}

so, i have some troubles. if text is small, then i catch unhandled exception at praogram's termination. if text is big, about 100+ symbols, i have exception at __**__.

do you have any suggestions, why it happens?

sorry for big code, it my first commit on StackOverFlow.

Answer 1

Use [] instead of () to new arrays:

double * cumulative = new double [k];
                                 ^ ^

(k) just makes a single place in memory and initializes it to k instead of making an array with size k.

 

Use [] for deleting arrays:

delete [] mass;
       ^^

 

You're using k, but I can't see where you initialized it ?!

for (int i=0; i<k; i++)

 

It's better to use std::vector instead of self defined arrays to avoid above problems.