Skip to main content
Code Golf

Return to Answer

replaced http://codegolf.stackexchange.com/ with https://codegolf.stackexchange.com/
Source Link
Community Bot
Community Bot
  • 1

Bash, 30 bytes

Since saeednsaeedn won't act on my suggestion – which is both shorter and faster than his approach – I thought I'd post my own answer:

seq 1e6|factor|awk '$0=$2*!$3'

How it works

seq 1e6

lists all positive integers up to 1,000,000.

factor

factors them one by one. For the first ten, the output is the following:

1:
2: 2
3: 3
4: 2 2
5: 5
6: 2 3
7: 7
8: 2 2 2
9: 3 3
10: 2 5

Finally,

awk '$0=$2*!$3'

changes the entire line ($0) to the product of the second field (the first prime factor) and the logical negation of the third field (1 if the is one prime factor or less, 0 otherwise).

This replaces lines corresponding to prime numbers with the number itself and all other lines with zeros. Since awk only prints truthy values, only prime number will get printed.

Bash, 30 bytes

Since saeedn won't act on my suggestion – which is both shorter and faster than his approach – I thought I'd post my own answer:

seq 1e6|factor|awk '$0=$2*!$3'

How it works

seq 1e6

lists all positive integers up to 1,000,000.

factor

factors them one by one. For the first ten, the output is the following:

1:
2: 2
3: 3
4: 2 2
5: 5
6: 2 3
7: 7
8: 2 2 2
9: 3 3
10: 2 5

Finally,

awk '$0=$2*!$3'

changes the entire line ($0) to the product of the second field (the first prime factor) and the logical negation of the third field (1 if the is one prime factor or less, 0 otherwise).

This replaces lines corresponding to prime numbers with the number itself and all other lines with zeros. Since awk only prints truthy values, only prime number will get printed.

Bash, 30 bytes

Since saeedn won't act on my suggestion – which is both shorter and faster than his approach – I thought I'd post my own answer:

seq 1e6|factor|awk '$0=$2*!$3'

How it works

seq 1e6

lists all positive integers up to 1,000,000.

factor

factors them one by one. For the first ten, the output is the following:

1:
2: 2
3: 3
4: 2 2
5: 5
6: 2 3
7: 7
8: 2 2 2
9: 3 3
10: 2 5

Finally,

awk '$0=$2*!$3'

changes the entire line ($0) to the product of the second field (the first prime factor) and the logical negation of the third field (1 if the is one prime factor or less, 0 otherwise).

This replaces lines corresponding to prime numbers with the number itself and all other lines with zeros. Since awk only prints truthy values, only prime number will get printed.

Source Link
Dennis
Dennis
  • 210.6k
  • 41
  • 370
  • 825

Bash, 30 bytes

Since saeedn won't act on my suggestion – which is both shorter and faster than his approach – I thought I'd post my own answer:

seq 1e6|factor|awk '$0=$2*!$3'

How it works

seq 1e6

lists all positive integers up to 1,000,000.

factor

factors them one by one. For the first ten, the output is the following:

1:
2: 2
3: 3
4: 2 2
5: 5
6: 2 3
7: 7
8: 2 2 2
9: 3 3
10: 2 5

Finally,

awk '$0=$2*!$3'

changes the entire line ($0) to the product of the second field (the first prime factor) and the logical negation of the third field (1 if the is one prime factor or less, 0 otherwise).

This replaces lines corresponding to prime numbers with the number itself and all other lines with zeros. Since awk only prints truthy values, only prime number will get printed.