求背包问题所有解(C++实现)

这是我学习数据结构时的一道上机作业，那时还没养成写注释的习惯，所以各位得受点苦了。

只是简易背包问题。

代码：

展开

  1 // 背包问题所有解
  2 // 作者:王锦 
  3 // 邮箱:jinksw@vip.qq.com
  4 
  5 #include "stdafx.h"
  6 #include <iostream>
  7 #include <stack>
  8 #include <list>
  9 using namespace std;
 10 
 11 class BagProblemSolver
 12 {
 13 private:
 14     int *stuffWeight;
 15     int s;
 16     int n;
 17     list<list<int>*> allResultHolder;//存放所有解
 18     void insertResultToList(stack<int> bagStack);
 19 public:
 20     BagProblemSolver(int s,int n,int *stuffWeight)
 21     {
 22         this->s = s;
 23         this->n = n;
 24         this->stuffWeight = new int[n];
 25         for(int i = 0;i < n;++i)
 26             this->stuffWeight[i] = stuffWeight[i];
 27     }
 28     ~BagProblemSolver()
 29     {
 30         delete[] stuffWeight;
 31     }
 32     list<list<int>*> getAllResult();
 33 };
 34 
 35 list<list<int>*> BagProblemSolver::getAllResult()
 36 {
 37     if(s <= 0)
 38         return allResultHolder;
 39     int currentWeight = 0;
 40     stack<int> indexStack;
 41     int i = 0;
 42     do
 43     {
 44         while(currentWeight < s && i < n)
 45         {
 46             if(currentWeight + stuffWeight[i] <= s)
 47             {
 48                 indexStack.push(i);
 49                 currentWeight += stuffWeight[i];
 50             }
 51             i++;
 52         }
 53         if(currentWeight == s)
 54         {
 55             insertResultToList(indexStack);
 56             i = indexStack.top();
 57             indexStack.pop();
 58             currentWeight -= stuffWeight[i];
 59             i++;
 60         }
 61         else if(!indexStack.empty())
 62         {
 63             i = indexStack.top();
 64             indexStack.pop();
 65             currentWeight -= stuffWeight[i];
 66             i++;
 67         }
 68     }while(!indexStack.empty() || i < n);
 69     return allResultHolder;
 70 }
 71 
 72 
 73 
 74 void BagProblemSolver::insertResultToList(stack<int> bagStack)
 75 {
 76     stack<int> tempStack;//用于将解以正序存入list
 77     while(!bagStack.empty())
 78     {
 79         tempStack.push(bagStack.top());
 80         bagStack.pop();
 81     }
 82     list<int> * resultList = new list<int>();
 83     while(!tempStack.empty())
 84     {
 85         resultList->push_back(stuffWeight[tempStack.top()]);
 86         tempStack.pop();
 87     }
 88     allResultHolder.push_back(resultList);
 89 }
 90 
 91 int _tmain(int argc, _TCHAR* argv[])
 92 {
 93     cout << "请输入背包可以放入的物品重量.(输入q退出)" << endl;
 94     char c;
 95     cin >> c;
 96     while(c != 'q')
 97     {
 98         cin.putback(c);
 99         int s = 0;
100         cin >> s;//背包可以放入的物品重量
101         cout << "请输入物品数量." << endl;
102         int n = 0;//物品数量
103         cin >> n;
104         int *stuffWeight= new int[n];
105         cout << "请分别输入" << n << "个物品重量." << endl;
106         for(int i = 0;i < n;++i)
107             cin >> stuffWeight[i];
108         BagProblemSolver test(s,n,stuffWeight);
109         list<list<int>*> ls = test.getAllResult();
110         cout << "背包容量(" << s << "),有(" << n << ")个物品,";
111         cout << "质量分别为(";
112         for(int i = 0; i < n;++i)
113         {
114             cout << stuffWeight[i];
115             if(i != n - 1)
116                 cout << ",";
117         }    
118         cout << ")" << endl;
119         if(ls.empty())
120         {
121             cout << "此问题无解!" << endl;
122         }
123         else
124         {
125             cout << "所有解为:" << endl;
126             while(!ls.empty())
127             {
128                 list<int> *temp = ls.front();
129                 ls.pop_front();
130                 while(!temp->empty())
131                 {
132                     cout << temp->front() << " ";
133                     temp->pop_front();
134                 }
135                 cout << endl;
136                 delete temp;
137             }
138         }
139         cout << "请输入背包可以放入的物品重量.(输入q退出)" << endl;
140         cin >> c;
141     }
142 }