CODEWITHSUNDEEP
c++
Nikola
Nikola

Reputation: 143

out_of_bounds: basic_string C++

I have to do a program, that takes parameters from the command line and makes the sum of N elements using the formula A(i)*x^(i). The Parameters from the command line are in the following sequence: x, n, A0....An. Function polynom() works, but function PrettyPrint() doesn't. It's purpose is to put a thousand separator by converting a double to a string and putting ",". After debugging the program, the value of the variable numString is what I expect it to be, however, when I tried to print it I get the following error message: (I also tried the code on another compiler and got the same result) 

terminate called after throwing an instance of 'std::out_of_range'
  what():  basic_string::replace: __pos (which is 4294967295) > this->size() (which is 12)

My code 

#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <stdlib.h>

using namespace std;

double polynom(vector<double> list) {
    // ToDo: Exercise 2.b - compute value of P(x)
    double result = 0;
    int i=0;
    while(i<=list[1]){
        result = result + (list[2+i] * pow(list[0],i));
        //cout<<list[i];
        i++;
    }
    return result;
}

void prettyPrint(double decimal)
{
    // ToDo: Exercise 2.c - print number with thousands separators to console   

    int count = 0;
    double decimal1 = decimal;
    while(decimal1>1){
        count++;                //find how many digits are before the .
        decimal1 = decimal1/10;
    }
    cout<<count<<endl;
    string numString = to_string(decimal);
    cout<< numString[count-1]<<endl;
    int i = count-1;
    while(i>=0){
        i -= 2;
        numString = numString.insert(i,",");
    }

    cout<<numString;
    //std::cout << decimal;
}

int main(int argc, char* argv[])
{
    // ToDo: Exercise 2.a - read parameters and x, deal with invalid values

    // ToDo: Exercise 2.b - print P(x)
    // ToDo: Exercise 2.c - print P(x) with prettyPrint
    vector<double> list;
    for ( int i = 1 ; i < argc ; i++){
        double tmp (stod(argv[i]));
        list.push_back(tmp); // add all arguments to the vector
    }

    if(list[1] < 1 || list[list.size()-1] == 0){
        cout<<"invalid arguments"<<endl; //terminate program if the arguments are not acceptable
        exit(1); 
    }

    cout<<polynom(list)<<endl;
    prettyPrint(polynom(list));
    std::cout << "Hello World";
    return 0;
}

Upvotes: 1

Views: 133

Answers (1)

MikeCAT
MikeCAT

Reputation: 75062

This part

while(i>=0){
    i -= 2;
    numString = numString.insert(i,",");
}

is wrong because you are using i after subtracting and before checking.

Adding checking will eliminate the problem.

while(i>=0){
    i -= 2;
    if (i > 0) numString = numString.insert(i,",");
}

Upvotes: 1

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