CODEWITHSUNDEEP
c++loopsvector
xampierre
xampierre

Reputation: 103

Loop over vector exits with error Process finished with exit code -1073741819

LE: In case it has any relevance i am using CLion. The program doesn't print anything.

I need to process a vector that contains vectors of string in the form of name card_type and display all cards in alphabetical order and the number of instances for each one. Output should look something like:

a_card 1
mastercard 4
visa 3

The code i have so far, that exits with error Process finished with exit code -1073741819 . What is the issue?

#include <iostream>
#include <vector>
#include <string>

void stats(const std::vector<std::vector<std::string>>& vec) {
    std::vector<std::pair<std::string, int>> orderedCards;

    for (const auto& client : vec){ //scan database for cards and make ordered vector of pairs
        if (orderedCards.empty()){ //insert first pair to empty vector
            orderedCards.push_back(std::make_pair(client[1],1));

        }else{ //for each new client scan vector and add new client/increment counter
        
           for (auto pair = orderedCards.begin(); pair != orderedCards.end(); ++pair){
               if (client[1][0] < pair->first[0]){ //compare first letter of new client and existing client
                   orderedCards.insert(pair, std::make_pair(client[1], 1));// if its smaller, insert in front
                   break;// break iteration and go for next client

               } else if (client[1] == pair->first){ //if theyre the same, increment counter
                   pair->second+=1;
                   break;

               } else if (pair+1 == orderedCards.end()) //if end is reached, there was no existing client thus add new one with high letter
                   orderedCards.push_back(std::make_pair(client[1], 1));
           }
        }
    }
    
    for (const auto& count : orderedCards)
        std::cout<<count.first<<" "<<count.second<<std::endl; //print on each line card and counter

}

std::vector<std::vector<std::string>> dataBase;


int main()
{
    dataBase={{"name", "bankcard"},{"name", "visa"},{"name", "bankcard"},{"name", "mastercard"},{"name", "bankcard"},{"name", "visa"}};
    
    stats(dataBase);

    return 0;
}

Upvotes: 3

Views: 108

Answers (2)

yaodav
yaodav

Reputation: 1276

@xampierre here a simpler function without using std::sort and the algorithm lib

void stats(const std::vector<std::vector<std::string>>& vec)
{

    std::map<std::string, int> orderedCards;
    for(auto & client : vec)
    {
        auto it = orderedCards.insert(std::make_pair(client[1],1));
        
        if (!it.second) // this means that the key was already in the map
            it.first->second+=1;
    }
    
   for (const auto& count : orderedCards)
        std::cout<<count.first<<" "<<count.second<<std::endl; //print on each line card and counter
}

Upvotes: 2

xampierre
xampierre

Reputation: 103

Thanks to @yaodav i switched from iterators to a map and sorting alg. Updated code with explanations:

#include <iostream>
#include <vector>
#include <string>

bool compare(const std::pair<std::string , int>& pair1, const std::pair<std::string , int>& pair2){
    return pair1.first[0] < pair2.first[0];
}

void stats(const std::vector<std::vector<std::string>>& vec) {
        std::map<std::string, int> map;

    for (const auto& client : vec){ //scan database for cards and make map
        auto ret = map.insert({client[1], 1});// insert new key:value pair

        if (!ret.second) // this means that the key was already in the map
            ret.first->second+=1; // dereferance pointer to key to access value and +=1
    }

    std::vector<std::pair<std::string, int>> orderedCards(map.begin(), map.end()); // make vector of pairs (key, value)
    std::sort(orderedCards.begin(), orderedCards.end(), compare); // sort vector according to defined compare

    for (const auto& count : orderedCards)
        std::cout<<count.first<<" "<<count.second<<std::endl;

}

std::vector<std::vector<std::string>> dataBase;


int main()
{
    dataBase={{"name", "bankcard"},{"name", "visa"},{"name", "bankcard"},{"name", "mastercard"},{"name", "bankcard"},{"name", "visa"}};
    
    stats(dataBase);

Upvotes: 0

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