组合数(2）获取C(n,k)组合数列表的QT实现

1)工程文件

QT = core

CONFIG += c++17 cmdline

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
        main.cpp

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

2）主程序

#include <QCoreApplication>
#include <vector>
#include <iostream>

using namespace std;
const int N = 10;
const int K = 5;

vector<vector<int>> getCombinationvector(int nums[],int ncount)
{
    vector<vector<int>> retvv = vector<vector<int>>();
    retvv.push_back(vector<int>());
    for (int n=0; n<ncount; n++) {
        int size = retvv.size();
        for (int i = 0; i < size; i++) {
            vector<int> newSub = vector<int>(retvv[i]);
            newSub.push_back(n);
            retvv.push_back(newSub);
        }
    }
    return retvv;
}

void showCombinationvector( vector<vector<int>> va )
{
    std::cout << "C(" << N <<"," << K <<") = " << va.size() << "\n";
    std::cout << "[ \n";
    for (int var = 0; var < va.size(); ++var) {
        std::cout << "  [ ";
        for(int j=0; j< va[var].size();j++)
        {
            std::cout << va[var][j] << " ";
        }
        std::cout << "]\n";
    }

    std::cout << "]\n";
}

vector<vector<int>> getCombineNK(int n, int k) {
    vector<int> nums = vector<int>();
    for(int i = 1; i < k + 1; ++i)
        nums.push_back(i);
    nums.push_back(n + 1);

    vector<vector<int>> retvv = vector<vector<int>>();
    int j = 0;
    while (j < k) {
        retvv.push_back(vector<int>(nums.begin(), nums.begin() + k));
        j = 0;
        while ((j < k) && (nums[j + 1] == nums[j] + 1))
        {
            nums[j] = j + 1;
            j++;
        }

        nums[j] ++ ;

    }
    return retvv;
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    int test[] = {1,2,3,4,5};
    //vector<vector<int>> va = getCombinationvector(test, 5);

    vector<vector<int>> va = getCombineNK(10, 5);

    showCombinationvector(va);
    return a.exec();
}

3）运行结果

C(10,5) = 252
[ 
  [ 1 2 3 4 5 ]
  [ 1 2 3 4 6 ]
  [ 1 2 3 5 6 ]
  [ 1 2 4 5 6 ]
  [ 1 3 4 5 6 ]
  [ 2 3 4 5 6 ]
  [ 1 2 3 4 7 ]
  [ 1 2 3 5 7 ]
  [ 1 2 4 5 7 ]
  [ 1 3 4 5 7 ]
  [ 2 3 4 5 7 ]
  [ 1 2 3 6 7 ]
  [ 1 2 4 6 7 ]
  [ 1 3 4 6 7 ]
  [ 2 3 4 6 7 ]
  [ 1 2 5 6 7 ]
  [ 1 3 5 6 7 ]
  [ 2 3 5 6 7 ]
  [ 1 4 5 6 7 ]
  [ 2 4 5 6 7 ]
  [ 3 4 5 6 7 ]
  [ 1 2 3 4 8 ]
  [ 1 2 3 5 8 ]
  [ 1 2 4 5 8 ]
  [ 1 3 4 5 8 ]
  [ 2 3 4 5 8 ]
  [ 1 2 3 6 8 ]
  [ 1 2 4 6 8 ]
  [ 1 3 4 6 8 ]
  [ 2 3 4 6 8 ]
  [ 1 2 5 6 8 ]
  [ 1 3 5 6 8 ]
  [ 2 3 5 6 8 ]
  [ 1 4 5 6 8 ]
  [ 2 45 6 8 ]
  [ 3 4 5 6 8 ]
  [ 1 2 3 7 8 ]
  [ 1 2 4 7 8 ]
  [ 1 3 4 7 8 ]
  [ 2 3 4 7 8 ]
  [ 1 2 5 7 8 ]
  [ 1 3 5 7 8 ]
  [ 2 3 5 7 8 ]
  [ 1 4 5 7 8 ]
  [ 2 4 5 7 8 ]
  [ 3 4 5 7 8 ]
  [ 1 2 6 7 8 ]
  [ 1 3 6 7 8 ]
  [ 2 3 6 7 8 ]
  [ 1 4 6 7 8 ]
  [ 2 4 6 7 8 ]
  [ 3 4 6 7 8 ]
  [ 1 5 6 7 8 ]
  [ 2 5 6 7 8 ]
  [ 3 5 6 7 8 ]
  [ 4 5 6 7 8 ]
  [ 1 2 3 4 9 ]
  [ 1 2 3 5 9 ]
  [ 1 2 4 5 9 ]
  [ 1 3 4 5 9 ]
  [ 2 3 4 5 9 ]
  [ 1 2 3 6 9 ]
  [ 1 2 4 6 9 ]
  [ 1 3 4 6 9 ]
  [ 2 3 4 6 9 ]
  [ 1 2 5 6 9 ]
  [ 1 3 5 6 9 ]
  [ 2 3 5 6 9 ]
  [ 1 4 5 6 9 ]
  [ 2 4 5 6 9 ]
  [ 3 4 5 6 9 ]
  [ 1 2 3 7 9 ]
  [ 1 2 4 7 9 ]
  [ 1 3 4 7 9 ]
  [ 2 3 4 7 9 ]
  [ 1 2 5 7 9 ]
  [ 1 3 5 7 9 ]
  [ 2 3 5 7 9 ]
  [ 1 4 5 7 9 ]
  [ 2 4 5 7 9 ]
  [ 3 4 5 7 9 ]
  [ 1 2 6 7 9 ]
  [ 1 3 6 7 9 ]
  [ 2 3 6 7 9 ]
  [ 1 4 6 7 9 ]
  [ 2 4 6 7 9 ]
  [ 3 4 6 7 9 ]
  [ 1 5 6 7 9 ]
  [ 2 5 6 7 9 ]
  [ 3 5 6 7 9 ]
  [ 4 5 6 7 9 ]
  [ 1 2 3 8 9 ]
  [ 1 2 4 8 9 ]
  [ 1 3 4 8 9 ]
  [ 2 3 4 8 9 ]
  [ 1 2 5 8 9 ]
  [ 1 3 5 8 9 ]
  [ 2 3 5 8 9 ]
  [ 1 4 5 8 9 ]
  [ 2 45 8 9 ]
  [ 3 4 5 8 9 ]
  [ 1 2 6 8 9 ]
  [ 1 3 6 8 9 ]
  [ 2 3 6 8 9 ]
  [ 1 4 6 8 9 ]
  [ 2 4 6 8 9 ]
  [ 3 4 6 8 9 ]
  [ 1 5 6 8 9 ]
  [ 2 5 6 8 9 ]
  [ 3 5 6 8 9 ]
  [ 4 5 6 8 9 ]
  [ 1 2 7 8 9 ]
  [ 1 3 7 8 9 ]
  [ 2 3 7 8 9 ]
  [ 1 4 7 8 9 ]
  [ 2 4 7 8 9 ]
  [ 3 4 7 8 9 ]
  [ 1 5 7 8 9 ]
  [ 2 5 7 8 9 ]
  [ 3 5 7 8 9 ]
  [ 4 5 7 8 9 ]
  [ 1 6 7 8 9 ]
  [ 2 6 7 8 9 ]
  [ 3 6 7 8 9 ]
  [ 4 6 7 8 9 ]
  [ 5 6 7 8 9 ]
  [ 1 2 3 4 10 ]
  [ 1 2 3 5 10 ]
  [ 1 2 4 5 10 ]
  [ 1 3 4 5 10 ]
  [ 2 3 4 5 10 ]
  [ 1 2 3 6 10 ]
  [ 1 2 4 6 10 ]
  [ 1 3 4 6 10 ]
  [ 2 3 4 6 10 ]
  [ 1 2 5 6 10 ]
  [ 1 3 5 6 10 ]
  [ 2 3 5 6 10 ]
  [ 1 4 5 6 10 ]
  [ 2 4 5 6 10 ]
  [ 3 4 5 6 10 ]
  [ 1 2 3 7 10 ]
  [ 1 2 4 7 10 ]
  [ 1 3 4 7 10 ]
  [ 2 3 4 7 10 ]
  [ 1 2 5 7 10 ]
  [ 1 3 5 7 10 ]
  [ 2 3 5 7 10 ]
  [ 1 4 5 7 10 ]
  [ 2 4 5 7 10 ]
  [ 3 4 5 7 10 ]
  [ 1 2 6 7 10 ]
  [ 1 3 6 7 10 ]
  [ 2 3 6 7 10 ]
  [ 1 4 6 7 10 ]
  [ 2 4 6 7 10 ]
  [ 3 4 6 7 10 ]
  [ 1 5 6 7 10 ]
  [ 2 5 6 7 10 ]
  [ 3 5 6 7 10 ]
  [ 4 5 6 7 10 ]
  [ 1 2 3 8 10 ]
  [ 1 2 4 8 10 ]
  [ 1 3 4 8 10 ]
  [ 2 3 4 8 10 ]
  [ 1 2 5 8 10 ]
  [ 1 3 5 8 10 ]
  [ 2 3 5 8 10 ]
  [ 1 4 5 8 10 ]
  [ 2 4 5 8 10 ]
  [ 3 4 5 8 10 ]
  [ 1 2 6 8 10 ]
  [ 1 3 6 8 10 ]
  [ 2 3 6 8 10 ]
  [ 1 4 6 8 10 ]
  [ 2 4 6 8 10 ]
  [ 3 4 6 8 10 ]
  [ 1 5 6 8 10 ]
  [ 2 5 6 8 10 ]
  [ 3 5 6 8 10 ]
  [ 4 5 6 8 10 ]
  [ 1 2 7 8 10 ]
  [ 1 3 7 8 10 ]
  [ 2 3 7 8 10 ]
  [ 1 4 7 8 10 ]
  [ 2 4 7 8 10 ]
  [ 3 4 7 8 10 ]
  [ 1 5 7 8 10 ]
  [ 2 5 7 8 10 ]
  [ 3 5 7 8 10 ]
  [ 4 5 7 8 10 ]
  [ 1 6 7 8 10 ]
  [ 2 6 7 8 10 ]
  [ 3 6 7 8 10 ]
  [ 4 6 7 8 10 ]
  [ 2 6 8 9 10 ]
  [ 3 6 8 9 10 ]
  [ 4 6 8 9 10 ]
  [ 5 6 8 9 10 ]
  [ 1 7 8 9 10 ]
  [ 2 7 8 9 10 ]
  [ 3 7 8 9 10 ]
  [ 4 7 8 9 10 ]
  [ 5 7 8 9 10 ]
  [ 6 7 8 9 10 ]
]