算法装载问题

算法设计与分析实验报告-

1.实验要求：

将n个集装箱装上载重量为c1和c2的轮船，其中集装箱总重量

3.程序代码

package javaapplication1;

import java.io.*;

public class Main {

static int n;

static int []w;

static int c1,c2;

static int cw;

static int bestw;

static int r;

static int []x;

static int []bestx;

public static int maxloading(int[]ww,int cc,int[]xx){

w=ww;

c1=cc;

bestw=0;

cw=0;

x=new int[n+1];

bestx=xx;

r=0;

for(int i=1;i<=n;i++)

r+=w[i];

backtrack(1);

return bestw;

}

private static void backtrack(int i){

if(i>n){ if(cw>bestw){

for(int j=1;j<=n;j++)

bestx[j]=x[j];

bestw=cw; }

return;

}

r-=w[i];

if(cw+w[i]<=c1){

x[i]=1;

cw+=w[i];

backtrack(i+1);

cw-=w[i];

}

if(cw+r>bestw){

x[i]=0;

backtrack(i+1);

}

r+=w[i]; }

public static void main(String[] args) throws IOException {

BufferedReader read =new BufferedReader(new InputStreamReader(new FileInputStream("input.txt")));

String a=new String();

a=read.readLine();

n=Integer.parseInt(a);

System.out.println("集装箱个数: "+n);

x=new int[n+1];

String[]b=new String[n];

a=read.readLine();

System.out.println("集装箱重量: "+a);

b=a.split(",");

w=new int[n+1];

for(int i=1;i<=n;i++){

w[i]=Integer.parseInt(b[i-1]);

}

a=read.readLine();

c1=Integer.parseInt(a);

a=read.readLine();

c2=Integer.parseInt(a);

System.out.println("轮船载重量: "+c1+","+c2);

int result= maxloading(w,c1,x);

int max,temp;

for(int i=1;i<3;i++){

for(int j=2;j<3;j++){

if(w[i]>w[j]){

temp=w[i];

w[i]=w[j];

w[j]=temp;

}

}

}

if((w[3]>c1)&&(w[3]>c2)){

System.out.println("都不可装");

}

else{System.out.println("轮船1装载的集装箱：");

for (int u=1;u

if(bestx[u]==1)

System.out.println(u+" ");

if(r>(result+c2))

System.out.println("轮船1可装："+result+" "+"轮船2装不完.");

else{

System.out.println("轮船2装载的集装箱：");

for (int u=1;u

if(bestx[u]==0)

System.out.println(u+" ");

System.out.println("最优装载--轮船1:"+result+" "+"轮船2:"+(r-result));

}

}

PrintWriter print=new PrintWriter(new OutputStreamWriter(new FileOutputStream("output.txt")));

if((w[3]>c1)&&(w[3]>c2)){

print.println("都不可装。");

}

else{

print.println("轮船1装载的集装箱：");

for (int u=1;u

if(bestx[u]==1)

print.println(u+" ");

if(r>(result+c2))

print.println("轮船1可装："+result+" "+"轮船2装不完。");

else{

print.println("轮船2装载的集装箱：");

for (int u=1;u

if(bestx[u]==0)

print.println(u+" ");

print.println("最优装载--轮船1:"+result+" "+"轮船2:"+(r-result));