动态规划求解0-1背包

  1 #include <stdio.h>
  2 #include <stdlib.h>
  3 
  4 int** DP(int num, int Weight, int*w, int *v);
  5 void output(int *c, int *w, int weight, int **ptr, int num);
  6 int main()
  7 {   
  8 
  9     
 10     int w[] = {3, 4, 7, 8, 9};
 11     int v[] = {4, 5, 10, 11, 13};
 12     int num = 5, weight = 17;
 13     int out[5] = {0};
 14     int i = 0, j = 0;
 15     int **ptr = NULL;
 16     
 17     ptr = DP(num, weight, w, v);
 18     output(out, w, weight, ptr, num);
 19 
 20     for(i = 0; i< num; i++)
 21     {
 22         for(j = 0; j < weight + 1; j++)
 23         {
 24             printf("%2d ", ptr[i][j]);
 25         }
 26         printf("\n");
 27         free(ptr[i]);
 28         ptr[i] = NULL;
 29     }
 30     printf("\n");
 31     free(ptr);
 32     ptr = NULL;
 33 
 34     for(i = 0; i < num; i++)
 35     {
 36         printf("%d ", out[i]);
 37     }
 38     printf("\n");
 39     system("pause");
 40     return 0;
 41 }
 42 
 43 
 44 int** DP(int num, int Weight, int*w, int *v)
 45 {
 46      int **arr = (int**)calloc(num, sizeof(int*));
 47      int i = 0, j = 0;
 48      for(i = 0; i < num; i++)
 49      {
 50          arr[i] = (int*)calloc(Weight + 1, sizeof(int));
 51      }
 52 
 53      for(i = 0; i < Weight + 1; i++)
 54      {
 55          arr[0][i] = 0;
 56      }
 57      for(i = 0; i < num; i++)
 58      {
 59          arr[i][0] = 0;
 60          for(j = 0; j < Weight + 1; j++)
 61          {  
 62              if(w[i] <= j)
 63              {   
 64                  if(i == 0)
 65                  {
 66                      arr[i][j] = v[i];
 67                  }
 68                  else
 69                  {
 70                      if(v[i] + arr[i - 1][j - w[i]] >= arr[i - 1][j])
 71                      {
 72                          arr[i][j] = v[i] + arr[i-1][j- w[i]];
 73                      }
 74                      else
 75                      {
 76                          arr[i][j] = arr[i - 1][j];
 77                      }
 78                  }     
 79              }
 80              else
 81              {   
 82                  if(i == 0)
 83                  {
 84                      arr[i][j] = 0;
 85                  }
 86                  else
 87                  {
 88                      arr[i][j] = arr[i - 1][j];
 89                  }
 90                  
 91              }
 92 
 93          }
 94      }
 95 
 96     return arr;
 97 }
 98 
 99 void output(int *c, int *w, int weight, int **ptr, int num)
100 {
101    int i = 0;
102 
103    for(i = num - 1; i >=1; i--)
104    {
105        if(ptr[i][weight] == ptr[i - 1][weight])
106        {
107            c[i] = 0;
108        }
109        else
110        {
111            c[i] = 1;
112            weight -= w[i];
113        }
114 
115     
116    }
117 
118    if(ptr[i][weight] == 0)
119    {
120        c[i] = 0;
121    }
122    else
123    {
124        c[i] = 1;
125    }
126 
127 }