struct IP
{
int a
char q1
int b
char q2
int c
char q3
int d
}s
void yesno()
{
scanf("%d%c%d%c%d%c%d",&s.a,&s.q1,&s.b,&s.q2,&s.c,&s.q3,&s.d)
if(s.a<256&&s.a>0&&s.b<256&&s.b>0&&s.c<256&&s.c>0&&s.d<256&&s.d>0)
{
if(s.q1=='.'&&s.q1=='.'&&s.q1=='.')printf("YES\n")
else printf("NO\n")
}
else printf("NO\n")
}
main()
{
int i
for(i=0i<99i++)
{yesno()}
}
可以试一下
#include <stdio.h>
int checkIP(const char* p)
{
int n[4]
char c[4]
if (sscanf(p, "%d%c%d%c%d%c%d%c",
&n[0], &c[0], &n[1], &c[1],
&n[2], &c[2], &n[3], &c[3])
== 7)
{
int i
for(i = 0 i < 3 ++i)
if (c[i] != '.')
return 0
for(i = 0 i < 4 ++i)
if (n[i] > 255 || n[i] < 0)
return 0
return 1
} else
return 0
}
int main()
{
const char* x[] =
{
"192.168.1.1",
"10.0.0.1.",
"127.256.0.1",
"iugerjiogjioe",
"172.16,0.1",
0
}
const char* m[] =
{
"是合法的IP地址"
}
int i = 0
while(x[i] != 0) {
printf("%s %s\n", x[i], m[checkIP(x[i])])
++i
}
return 0
}
