C program to print combination of 4 digits number

C program to print combination of 4 digits number

Output:

Enter the 4-digit number: 1234
1234
234
134
34
124
24
14
4
123
23
13
3
12
2
1

Implementation:

#include <stdio.h> int main(void) { /* enter the numbers in the array for which you want to find combinations */ char a[5]; printf("Enter the 4-digit number:\n"); scanf("%s",a); /* determine the number of combinations 2^(number of elements) -1 here, =pow(2,3)-1(since, 3 elements are there,viz.,1,2,3) =8-1 =7 */ int s=15; int t; int i; while(s) { t=s; /* until the number of elements of the array change the condition according to your size of the array here,it is always 4(since 4 - digit number) */ for(i=0;i<4;i++) { if(t&1) printf("%c",a[i]); t>>=1; } s--; printf("\n"); } return 0; }