How to find the count number of entries in map iterator in C-CodePudding

I am new in C .I am using STL Containers.I am mapping the AnimalWeightCAT to unique values of distance travel in km.Using this code

#include <iostream>
#include <map>
#include <sstream>

int main() {
    std::istringstream file(
        "3 138 3 239 3 440 3 241 3 462 3 432 3 404 2 435 2 514 2 565 3 328 3 "
        "138 5 401 5 142 5 404 5 460 5 472 2 418 5 510 2");

    // some typedefs to make it simpler:
    typedef int AnimalWeightCAT_t;
    typedef int distance_t;
    typedef int count_t;
    typedef std::map<distance_t, count_t> distcount_t;
    typedef std::map<AnimalWeightCAT_t, distcount_t> AWeightDistance;

    AWeightDistance AWeightDistanceCount; // map AnimalWeightCAT -> distances with counts
    
    AnimalWeightCAT_t AnimalWeightCAT;       // temporary variable to read a AnimalWeightCAT
    distance_t dist; // temporary variable to read a distance

    // read AnimalWeightCAT and distance until the file is depleated and use AnimalWeightCAT and dist as
    // keys in the outer and inner map and increase the count:
    while (file >> AnimalWeightCAT >> dist)   AWeightDistanceCount[AnimalWeightCAT][dist];

    for(AWeightDistance::iterator adit= AWeightDistanceCount.begin(); adit!= AWeightDistanceCount.end();   adit) {
        std::cout << "AnimalWeightCAT: " << adit->first << '\n';
        for(distcount_t::iterator dcit = adit->second.begin();dcit != adit->second.end();  dcit){
            std::cout << '\t' << dcit->first << ' ' << dcit->second << '\n';
        }
    }
}

How i can find the count of number of distict in indices of AnimalWeightCAT of iterator aditby using map in C ? Above code display the following output

Output:

AnimalWeightCAT: 2   
    418 1
    435 1
    514 1
    565 1
AnimalWeightCAT: 3
    138 2
    239 1
    241 1
    328 1
    404 1
    432 1
    440 1
    462 1
AnimalWeightCAT: 5
    142 1
    401 1
    404 1
    460 1
    472 1
    510 1

I want this kind of output.How?

AnimalWeightCAT: 2   count = 4
AnimalWeightCAT: 3   count = 8
AnimalWeightCAT: 5   count = 6

CodePudding user response：

For count of the second map adit->second.size() will be sufficient so your last loop, in order to look like you desire must be:

for(AWeightDistance::iterator adit = AWeightDistanceCount.begin();
    adit != AWeightDistanceCount.end();   adit)
{
    std::cout << "AnimalWeightCAT: " << adit->first
              << "  count: " << adit->second.size() << '\n'; 
}

or simpler, using a range based for-loop:

for(auto&&[awc, dist_count] : AWeightDistanceCount) {
    std::cout << "AnimalWeightCAT: " << awc
              << "  count: "<< dist_count.size() << '\n'; 
}