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 = coreCONFIG += 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 6.0.0SOURCES += \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;vector<vector<int>> getCombinationList(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 showCombinationList( vector<vector<int>> 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};vector<vector<int>> 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 ]
]