prime.c revision 89751
1219820Sjeff/* 2219820Sjeff * Prime number generator. It prints on stdout the next prime number 3219820Sjeff * higher than the number specified as argv[1]. 4219820Sjeff */ 5219820Sjeff 6219820Sjeff#include <stdio.h> 7219820Sjeff#include <math.h> 8219820Sjeff 9219820Sjeffmain(argc, argv) 10219820Sjeff 11219820Sjeffint argc; 12219820Sjeffchar *argv[]; 13219820Sjeff 14219820Sjeff{ 15219820Sjeff double i, j; 16219820Sjeff int f; 17219820Sjeff 18219820Sjeff if (argc < 2) 19219820Sjeff { 20219820Sjeff exit(1); 21219820Sjeff } 22219820Sjeff 23219820Sjeff i = atoi(argv[1]); 24219820Sjeff while (i++) 25219820Sjeff { 26219820Sjeff f=1; 27219820Sjeff for (j=2; j<i; j++) 28219820Sjeff { 29219820Sjeff if ((i/j)==floor(i/j)) 30219820Sjeff { 31219820Sjeff f=0; 32219820Sjeff break; 33219820Sjeff } 34219820Sjeff } 35219820Sjeff if (f) 36219820Sjeff { 37219820Sjeff printf("%.0f\n", i); 38219820Sjeff exit(0); 39219820Sjeff } 40219820Sjeff } 41219820Sjeff} 42219820Sjeff