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44 lines
828 B
C
44 lines
828 B
C
/* Prime number - Program to check whether a given number is prime or not */
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/* Assume 2 is a prime number but 0 and 1 are not */
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#include <stdio.h>
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#include <conio.h>
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void main()
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{
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int p,d, flag ;
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clrscr() ;
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printf("Enter a number: ") ;
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scanf("%d", &p) ;
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flag=1 ; /* Assuming p is prime */
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for(d=2 ; d<=p-1 ; d++) /* d<=p/2 is also correct */
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if(p%d==0) /* True if number is not prime */
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{
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flag=0 ;
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break ; /* Loop terminates if p is not prime */
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}
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if(flag==0 || p==1 || p==0 )
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printf("%d is not prime", p) ;
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else
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printf("%d is prime", p) ;
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getch() ;
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}
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/*
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Output 1:
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Enter a number: 1
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1 is not prime
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Output 2:
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Enter a number: 7
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7 is prime
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Output 3:
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Enter a number: 9
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9 is not prime
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*/
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