C的装箱问题，谁有思路！

doer_ljy 2003-03-12 09:31:30

C的装箱问题，谁有思路！

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doer_ljy 2003-03-12

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kingofvc(现实就是不公)兄，这的份不够分的！
令开一个贴子，单独给分！
呵呵！
http://expert.csdn.net/Expert/topic/1519/1519843.xml?temp=.3213617

cicirain 2003-03-12

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only 蹭分~~ :P

kingofvc 2003-03-12

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更正 “你可以把堆栈改成对了 ” 应为你可以把堆栈改成队列

kingofvc 2003-03-12

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另外一点我使用了goto 主要是偷懒希望你不要这么做：）
后来我用同样的算法帮同学写了一个c的不过我这里已经没有原程序了（没用goto）

kingofvc 2003-03-12

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背包问题啊运筹学分支定界法不过由于当时误解了算法使用了堆栈影响了程序的效率
你可以把堆栈改成对了然后把堆栈的弹出改为队列中取最大值即可
这里主要是解决第一种问题对于第二种其实也在程序的过程中
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <stack>
#include <float.h>
using namespace std;
class CNode {//存放节点信息主要用于堆栈
public:
CNode(int number){
value=0;
pos=0;
pGood=new int[number];
memset(pGood,0,number*sizeof(int));
}
~CNode(){
if(pGood!=NULL)
delete []pGood;
}
double value;
int pos;
int *pGood;
};
class CGood{//存放物品信息
public :
CGood(int number){
num=number;
average=new double[number];
pWeight=new double[number];
pValue=new double[number];
no=new int[number];
}
~CGood(){
if(pWeight!=NULL)
delete []pWeight;
if(pValue!=NULL)
delete []pValue;
if(average!=NULL)
delete []average;
if(no!=NULL)
delete []no;
}
void GetData(){
for(int i=0;i<num;i++){
cout<<"请输入物品"<<i+1<<"的重量:"<<endl;
cin>>pWeight[i];
cout<<"请输入物品"<<i+1<<"的价值:"<<endl;
cin>>pValue[i];
average[i]=pValue[i]/pWeight[i];
no[i]=i;
}
}
void ShowAll(){
for(int i=0;i<num;i++){
cout<<"物品"<<no[i]+1<<" 重"<<pWeight[i]<<" 价值"<<pValue[i]<<" 平均价值"<<average[i]<<endl;
}
}
void Sort(){
for(int i=0;i<num;i++){
double min=average[0];
int pos=0;
for(int j=0;j<num-i;j++){
if(min>average[j]){
min=average[j];
pos=j;
}
}
double temw=pWeight[num-i-1];
double temv=pValue[num-i-1];
double tema=average[num-i-1];
int temn=no[num-i-1];
pWeight[num-i-1]=pWeight[pos];
pValue[num-i-1]=pValue[pos];
average[num-i-1]=average[pos];
no[num-i-1]=no[pos];
pWeight[pos]=temw;
pValue[pos]=temv;
average[pos]=tema;
no[pos]=temn;
}
}
double GetWeight(){
double all=0;
for(int i=0;i<num;i++)
all+=pWeight[i];
return all;
}
double GetValue(){
double all=0;
for(int i=0;i<num;i++)
all+=pValue[i];
return all;
}
double GetMinWeight(){
double min=pWeight[0];
for(int i=1;i<num;i++)
if(min>pWeight[i])
min=pWeight[i];
return min;
}
int num;
double *average;
double *pWeight;
double *pValue;
int *no;
};
stack <double> mystack;
stack <int> datastack;
void main(){
CNode *one,*another;
double weight;
cout<<"请输入总共允许的货物总量:"<<endl;
cin>>weight;
int number;
cout<<"请输入物品个数:"<<endl;
cin>>number;
one=new CNode(number);
another=new CNode(number);
CNode max(number);
CGood all(number);
all.GetData();
while(all.GetWeight()<weight){
cerr<<"物品总共重量小于允许所带物品的总量!无意义"<<endl<<"请重新输入:"<<endl;
all.GetData();
}
while(all.GetMinWeight()>weight){
cerr<<"物品最小重量大于于允许所带物品的总量!无意义"<<endl<<"请重新输入:"<<endl;
all.GetData();
}
all.ShowAll();
all.Sort();
cout<<"排序以后:"<<endl;
all.ShowAll();
loop:
do {
int pos=one->pos;
one->pGood[pos]=1;
another->pGood[pos]=-1;
double oneweight=0;
double anotherweight=0;
int i;
double readlyone=0;
double readlyanother=0;
one->value=0;
another->value=0;
for(i=0;i<=pos;i++){
if(one->pGood[i]==1){
oneweight+=all.pWeight[i];
one->value+=all.pValue[i];
}
if(another->pGood[i]==1){
anotherweight+=all.pWeight[i];
another->value+=all.pValue[i];
}
}
readlyone=oneweight;
readlyanother=anotherweight;
int j=i;
while(oneweight<=weight&&i<number){
oneweight+=all.pWeight[i];
one->value+=all.pValue[i];
i++;
}
while(anotherweight<=weight&&j<number){
anotherweight+=all.pWeight[j];
another->value+=all.pValue[j];
j++;
}
i--;
j--;
if(!(i==number-1&&j==number-1)){
one->value-=(all.average[i]*(oneweight-weight));
another->value-=(all.average[j]*(anotherweight-weight));
}
if(readlyone>weight)
one->value=-DBL_MAX;
if(readlyanother>weight)
another->value=-DBL_MAX;
cout<<"one value:"<<one->value<<endl<<"another value:"<<another->value<<endl<<endl;
if(one->value>=another->value){
if(another->value!=-DBL_MAX){
cout<<"push another "<<another->value<<endl;
mystack.push(another->value);
datastack.push(another->pos);
for(int j=0;j<number;j++)
datastack.push(another->pGood[number-j-1]);
}
for(int i=0;i<number;i++)
another->pGood[i]=one->pGood[i];
another->pos=one->pos;
}
else{
if(one->value!=-DBL_MAX){
cout<<"push one "<<one->value<<endl;
mystack.push(one->value);
datastack.push(one->pos);
for(int j=0;j<number;j++)
datastack.push(one->pGood[number-j-1]);
}
for(int i=0;i<number;i++)
one->pGood[i]=another->pGood[i];
one->pos=another->pos;
}
one->pos++;
another->pos=one->pos;
if(pos==number-1){
CNode *p=one->value>another->value? one:another;
max.value=p->value;
double maxweight=0;
for(i=0;i<number;i++){
max.pGood[i]=p->pGood[i];
if(p->pGood[i]==1)
maxweight+=all.pWeight[i];
}
if(maxweight>weight)
max.value=-DBL_MAX;
}
} while(one->pGood[number-1]==0);
while(!mystack.empty()){
one->value=mystack.top();
for(int i=0;i<number;i++){
one->pGood[i]=datastack.top();
datastack.pop();
}
one->pos=datastack.top()+1;
datastack.pop();
mystack.pop();
if(max.value<one->value){
mystack.push(max.value);
datastack.push(max.pos);
for(int j=0;j<number;j++)
datastack.push(max.pGood[number-j-1]);
for(int i=0;i<number;i++){
another->pGood[i]=one->pGood[i];
another->pos=one->pos;
}
goto loop;
}
}
cout<<"value:"<<max.value<<endl<<"选择的物品是"<<endl;
for(int j=0;j<number;j++)
if(max.pGood[j]==1)
cout<<all.no[j]+1<<"\t";
cout<<endl;
system("pause");
}

doer_ljy 2003-03-12