/
main.c
90 lines (76 loc) · 1.59 KB
/
main.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
/* Name: aprime
Author: Blake Bartenbach
Description: primality test program */
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<stdint.h>
#include<stdbool.h>
#include<ctype.h>
void print_header();
void print_version();
void cmd_handler(char *cmd);
void primality_handler();
void assess_primality(int n);
int get_number();
const char *version = "0.0.3-indev";
int i;
int main() {
print_header();
while (1) {
printf("(aprime) ");
char cmd[20];
fgets(cmd, sizeof(cmd), stdin);
bool integer = true;
for (i=0; i < strlen(cmd)-1; i++) {
if (!isdigit(cmd[i])) {
integer = false;
break;
}
}
if (integer == true) {
int input;
sscanf(cmd, "%d", &input);
assess_primality(input);
} else {
cmd_handler(cmd);
}
}
}
void print_header() {
printf("aprime - primality test program version %s\n\n", version);
}
void cmd_handler(char *cmd) {
if (strncmp(cmd, "exit", 4) == 0) {
exit(0);
}
}
void primality_handler() {
int retVal = 1;
while (retVal == 1) {
retVal = get_number();
}
exit(1);
}
int get_number() {
printf("(aprime) ");
unsigned int ret, num;
ret = scanf("%u", &num);
assess_primality(num);
return ret;
}
void assess_primality(int n) {
if ( n < 2 ) {
printf(" [[ %d is not prime (less than 2) ]]\n", n);
return;
}
double m = n * 0.5;
int i;
for (i = 2; i <= m; i++) {
if ( n != i && n % i == 0) {
printf(" [[ %d is not prime (divisible by %d]]\n", n, i);
return;
}
}
printf(" [[ %d is prime ]]\n", n);
}