C语言求三位数的回文数,回文数 C语言求解
#9
unsigned long getRevNum(unsigned long x, int n)
{
unsigned long y=0;
for(i=0;i
{ y*=10;
y+=x%10;
}
return y;
}
unsigned long sumrev(unsigned long x, int n)
return x+ getRevNum(x,n);
)
int isplalindrome(unsigned long x,int n)
{ int i,j=1;
int res=1;
for(i=1;i
if(x
for(i=10;i<=j;i*=10,j/=10)
{
if(x/j ==x%i){res=0;break;}
}
return res;
}
int is_8plalindrome(unsigned long x)
{
int n=2;
unsigned long t=x;
unsigned long v=100;
if(x<12)return -2;//比12小
if(x>100)return -1;//比100 大
if(x==100)return 1;//101 是回文，假设是
for(i=0;i<8;i++)
{
x=sumrev( x,n);
if(x>v){
n++;
v*=10;
}
if(isplalindrome(x,n))return i+1;
}
return 0;
}
int main()
{
unsigned long x ,t;
int sucess= scanf("%u",&x);
while {sucess >0 && (x<=100 && x>=12))
{
t=is_8plalindrome(x);
if(t>=0)
printf("%u ",t);
sucess = scanf("%u",&x);
}
return 0;
}
#9 unsigned long getRevNum(unsigned long x, int n) { unsigned long y=0; for(i=0;i { y*=10; y+=x%10; } return y; } unsigned long sumrev(unsigned long x, int n) return x+ getRevNum(x,n); ) int isplalindrome(unsigned long x,int n) { int i,j=1; int res=1; for(i=1;i if(x for(i=10;i<=j;i*=10,j/=10) { if(x/j ==x%i){res=0;break;} } return res; } int is_8plalindrome(unsigned long x) { int n=2; unsigned long t=x; unsigned long v=100; if(x<12)return -2;//比12小 if(x>100)return -1;//比100 大 if(x==100)return 1;//101 是回文，假设是 for(i=0;i<8;i++) { x=sumrev( x,n); if(x>v){ n++; v*=10; } if(isplalindrome(x,n))return i+1; } return 0; } int main() { unsigned long x ,t; int sucess= scanf("%u",&x); while {sucess >0 && (x<=100 && x>=12)) { t=is_8plalindrome(x); if(t>=0) printf("%u ",t); sucess = scanf("%u",&x); } return 0; }