01背包问题-状态d[i][j],f[i][j],滚动数组--java实现

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package com.supermars.practice;

import java.util.Scanner;

public class 背包01问题d {
   /*
   *
   5 100
   77 92
   22 22
   29 87
   50 46
   99 90
   133
   *
   */
   static Scanner cin = new Scanner(System.in);

   public static void main(String[] args) {
       // i层剩余容量j
       // d[i,j]=max{d(i+1,j),d(i+1,j-V[i])+W[i])}
       while (cin.hasNext()) {
           int n = cin.nextInt();
           int C = cin.nextInt();
           int V[] = new int[n+1];
           int W[] = new int[n+1];
           int d[][] = new int[C+1][C+1];// 目标状态d
           for (int i = 0; i < n; i++) {
               V[i] = cin.nextInt();
               W[i] = cin.nextInt();
           }

           for (int i = n; i >= 1; i--) {// 层
               for (int j = 0; j <= C; j++) {// 剩余量
                   d[i][j] = (i == 0 ? 0 : d[i + 1][j]);// 不选
                   if (j >= V[i]) // 选择该层
                       d[i][j] = Math.max(d[i][j], d[i + 1][j - V[i]] + W[i]);
               }

           }

           System.out.println(d[1][C]);

       }
   }

}

------------------------

package com.supermars.practice;

import java.util.Scanner;

public class 背包01问题规划方向f {
   static Scanner cin = new Scanner(System.in);

   public static void main(String[] args) {
       // i层剩余容量j
       // d[i,j]=max{d(i+1,j),d(i+1,j-V[i])+W[i])}
       while (cin.hasNext()) {
           int n = cin.nextInt();
           int C = cin.nextInt();
           int V[] = new int[n + 1];
           int W[] = new int[n + 1];
           int f[][] = new int[C + 1][C + 1];// 目标状态d
           for (int i = 0; i < n; i++) {
               V[i] = cin.nextInt();
               W[i] = cin.nextInt();
           }
           //f(i,j)=max{f(i-1,j),f(i-1,j-V[i])+W[i]}

           for (int i =1; i <=n; i++) {//层
               for (int j = 0; j <=C; j++) {//当前量
                   f[i][j]=(i==1?0:f[i-1][j]); //不选
                   if(j>=V[i]){       //选择
                       f[i][j]=Math.max(f[i][j],f[i-1][j-V[i]]+W[i]);
                   }

               }
           }

           System.out.println(f[n][C]);



       }
   }
}

------------------------

package com.supermars.practice;

import java.util.Scanner;

public class 背包01滚动数组 {
   static Scanner cin = new Scanner(System.in);

   public static void main(String[] args) {
       // i层剩余容量j
       // d[i,j]=max{d(i+1,j),d(i+1,j-V[i])+W[i])}
       while (cin.hasNext()) {
           int n = cin.nextInt();
           int C = cin.nextInt();
           int V[] = new int[n + 1];
           int W[] = new int[n + 1];
           int f[] = new int[C + 1];// 目标状态d
           for (int i = 0; i < n; i++) {
               V[i] = cin.nextInt();
               W[i] = cin.nextInt();
           }
           // f(i,j)=max{f(i-1,j),f(i-1,j-V[i])+W[i]}

           for (int i = 1; i <= n; i++) {// 层
               for (int j = C; j >= 0; j--) {// 当前量
                   if (j >= V[i])
                       f[j] = Math.max(f[j], f[j - V[i]] + W[i]);
               }
           }

           System.out.println(f[C]);

       }
   }
}

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