Segmentation fault (core dumped) error, can't assign vector

[tanveer00]

#include<iostream>
#include<string>
#include<sstream>
#include<vector>
#include<algorithm>
using namespace std;
int main()
{
    string indexArray;
    string input, line;
    int test_case, number, i;
    vector <int> index;
    vector <float> input1;
    vector <float> input2;
    float output;

    getline(cin,line);
    stringstream(line) >> test_case;
    //cin>>test_case;
    cout<<endl;
    while(test_case--)
    {
        getline(cin,indexArray);
        stringstream iss(indexArray);
        getline(cin, input);
        stringstream iss1(input);
        while(iss>>number)
        {
            index.push_back(number);
        }
        while(iss1>>output)
        {
            input1.push_back(output);
        }
        for(i=0; i<index.size(); i++)
        {
            cout<<index[i]<<" ";
        }
        cout<<index.size()<<endl;
        for(i=0; i<input1.size(); i++)
        {
            cout<<input1[i]<<" ";
        }
        cout<<input1.size()<<endl;

        
        for(i=0; i<index.size(); i++)
        {
            
            input2[index[i]-1]=input1[i];
        }
        
        for(int i=0; i<input1.size(); i++)
        {
            cout<<input2[i]<<" ";
        }
        cout<<endl;

        input1.clear();
        index.clear();
    }
}

My program crashes at line 50 where,
input2[index[i] - 1]=input1[i]

I can't seem to understand why

[MiiNiPaa]

input2 has 0 elements, so you cannot access it by using []. You need to fill it with numbers first.

[tanveer00]

Well I AM trying to fill input2 with numbers by assigning input1 members to input2. Am I missing something?

[MiiNiPaa]

Yes, operator[] exist to allow access to existing elements. You should look at resize() method.

[tanveer00]

So, should I write vectorSample.resize(size_type n) everytime I initialize a vector to fill it up with numbers (0 in this case) ?

[MiiNiPaa]

you should resize vector to make space for all objects you want to store in it. So you want to pass largest number found in index vector to make sure that you can acces value under that index.