Power Set 

This example shows generating power set for the user given set. A powset is the one which contains all possible subsets of given set.

File Name  :   source/C/advanced/power_set.c  Author  :   Sudhakar KV Email  :   kvenkatasudhakar@gmail.com

view sourceprint? 01 #include<stdio.h> 02 #include<conio.h> 03   04 void print_set(int size, int *array, int n) { 05        06      //printf("\nfor num : %d", n); 07        08      int i, ele_count = 0; 09      printf("{"); 10        11      for(i=0; i < size; i++) { 12          if (n %2 == 1) { 13                  14              if (ele_count != 0) { 15                  printf(", "); 16              }  17              printf("%d", array[i]);  18              ele_count ++; 19          } 20            21          n = n/2; 22      } 23        24      printf("}");     25 } 26   27   28 void print_powerset(int size, int *array) { 29   30      int max = pow(2, size); 31      int i; 32        33      printf("{ "); 34      for(i=0; i < max; i++) { 35            36          if (i > 0) { 37              printf(", "); 38          } 39          print_set(size, array, i); 40      } 41      printf(" }"); 42 } 43   44   45 int main(int argc, char *argv[]) { 46    int i, n, *array;    47    printf("Enter the size of the integer set: "); 48    scanf("%d", &n); 49      50    array=(int *)malloc(sizeof(int)); 51   52     printf("\nEnter the elements of the set : "); 53     for(i=0;i<n;i++) 54     { 55      scanf("%d", &array[i]); 56     } 57      58    print_powerset(n, array); 59    getch(); 60 }

Enter the size of the integer set: 6

Enter the elements of the set : 1 2 3 4 5 6
{ {}, {1}, {2}, {1, 2}, {3}, {1, 3}, {2, 3}, {1, 2, 3}, {4}, {1, 4}, {2, 4}, {1,
 2, 4}, {3, 4}, {1, 3, 4}, {2, 3, 4}, {1, 2, 3, 4}, {5}, {1, 5}, {2, 5}, {1, 2,
5}, {3, 5}, {1, 3, 5}, {2, 3, 5}, {1, 2, 3, 5}, {4, 5}, {1, 4, 5}, {2, 4, 5}, {1
, 2, 4, 5}, {3, 4, 5}, {1, 3, 4, 5}, {2, 3, 4, 5}, {1, 2, 3, 4, 5}, {6}, {1, 6},
 {2, 6}, {1, 2, 6}, {3, 6}, {1, 3, 6}, {2, 3, 6}, {1, 2, 3, 6}, {4, 6}, {1, 4, 6
}, {2, 4, 6}, {1, 2, 4, 6}, {3, 4, 6}, {1, 3, 4, 6}, {2, 3, 4, 6}, {1, 2, 3, 4,
6}, {5, 6}, {1, 5, 6}, {2, 5, 6}, {1, 2, 5, 6}, {3, 5, 6}, {1, 3, 5, 6}, {2, 3,
5, 6}, {1, 2, 3, 5, 6}, {4, 5, 6}, {1, 4, 5, 6}, {2, 4, 5, 6}, {1, 2, 4, 5, 6},
{3, 4, 5, 6}, {1, 3, 4, 5, 6}, {2, 3, 4, 5, 6}, {1, 2, 3, 4, 5, 6} }