Integer to binary char array

void intToBinary(int num, char* string)
{
    string[32] = '\0';
    int i,j;
    int temp = num;

    // is num negative?
    int isNegative = num < 0 ? 1 : 0;

    //negate all bits and add 1 (two complements)
    if(isNegative)
    {
        temp = -1 * temp; //absolute value

        //In order to get the negative number in
        // 2's complement you can either negate and
        // increment, or decrement by 1 and negate.
        //In this function, temp gets negated after
        //the conversion to string
        --temp;
    }

    //Write binary of positive num to string
    for(i = 0, j = 31; i < 32; i++,j--)
    {
        if(pow(2,j) <= temp)
        {
           //Temp is decreased when the bit is 1
           temp = temp - pow(2, j);
           string[i] = '1';
        }
        else
        {
            //Nothing happens to temp when the bit is 0
            string[i] = '0';
        }
    }

    if(isNegative)
    {
        for(i = 0; i < 32; i++)
        {
            //negate bits
            string[i] = string[i] == '1' ? '0' : '1';
        }
    }
}