组合数（1） 用Vector实现获取所有组合数列表的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 
#include 
#include 
 
using namespace std;
 
 
vectorint>> getCombinationList(int nums[],int ncount)
{
    vectorint>> retvv = vectorint>>();
    retvv.push_back(vector<int>());
    for (int n=0; 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 showCombinationList( vectorint>> va )
{
    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";
}
 
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
 
    int test[] = {1,2,3,4,5};
    vectorint>> va = getCombinationList(test, 5);
 
    showCombinationList(va);
    return a.exec();
}

3.执行结果

[ 
  [ ]
  [ 0 ]
  [ 1 ]
  [ 0 1 ]
  [ 2 ]
  [ 0 2 ]
  [ 1 2 ]
  [ 0 1 2 ]
  [ 3 ]
  [ 0 3 ]
  [ 1 3 ]
  [ 0 1 3 ]
  [ 2 3 ]
  [ 0 2 3 ]
  [ 1 2 3 ]
  [ 0 1 2 3 ]
  [ 4 ]
  [ 0 4 ]
  [ 1 4 ]
  [ 0 1 4 ]
  [ 2 4 ]
  [ 0 2 4 ]
  [ 1 2 4 ]
  [ 0 1 2 4 ]
  [ 3 4 ]
  [ 0 3 4 ]
  [ 1 3 4 ]
  [ 0 1 3 4 ]
  [ 2 3 4 ]
  [ 0 2 3 4 ]
  [ 1 2 3 4 ]
  [ 0 1 2 3 4 ]
]