学步园

# include<stdio.h><br /> # include<stdlib.h><br /> # include<string.h><br /> # include<math.h><br /> unsigned long data[2000] ;<br /> int count;<br /> char str[20];<br /> char str1[20];<br /> char str2[20]; </p> <p>int cmp(const void *a,const void *b)<br /> {<br /> return *(unsigned long *)a-*(unsigned long *)b;<br /> } </p> <p>int issushu(unsigned long num)<br /> { </p> <p> unsigned long i,j ,k = num; </p> <p> for (j = (unsigned long)sqrt(k),i = 2;i <= j+1;i++)<br /> if (num%i==0)<br /> return 0; </p> <p> return 1; </p> <p>}<br /> void _itoah(int n,int digit )<br /> {<br /> int i = 0;<br /> for(i = 0;i < digit;i ++)<br /> {<br /> //str[digit-i-1] = n%10 + '0';<br /> str[digit-i-1] = n%10 + '0';<br /> n /=10;<br /> } </p> <p>}<br /> void _itoad(int n,int digit,int b )// 针对 奇数和偶数的不同 增加一个标志位<br /> {<br /> int i = 0,j = digit;<br /> if(b==1)<br /> digit ++;<br /> for(i = 0;i < j;i ++)<br /> {<br /> str[digit++] = n%10 + '0';<br /> n /=10;<br /> }<br /> }<br /> void even_huiwen(int n)<br /> {<br /> long i ,j,digit = n/2,tmp = 0;<br /> //j = (long)pow(10,digit) -1;<br /> j = (long)pow(10,digit) -1;<br /> for(i = (long)pow(10,digit-1); i <= j;i++ ) //i代表偶数的高位//(long)pow(10,n-1); i <= j;i++ )<br /> { </p> <p> _itoah(i,digit);<br /> _itoad(i,digit,0);<br /> str[n] = '/0';<br /> strcpy(str1,str);<br /> strrev(str1);<br /> if (!strcmp(str1,str)) if(issushu(atol(str)))<br /> data[count ++] = atol(str);//printf("%ld/t",atol(str)),data[count ++] = atol(str); </p> <p> memset(str,NULL,sizeof(str));<br /> memset(str1,NULL,sizeof(str1)); </p> <p> }<br /> }<br /> void odd_huiwen(int n)<br /> {<br /> long i ,j,k,digit = n/2,tmp = 0;<br /> j = (long)pow(10,digit) -1; </p> <p> for(k = 0;k < 10; k ++) // 奇数位中间的数字<br /> for (i = (long)pow(10,digit-1);i <= j ; i ++)<br /> {<br /> _itoah(i,digit);<br /> str[digit] = k + '0';<br /> _itoad(i,digit,1);<br /> str[n] = '/0';<br /> strcpy(str1,str);<br /> strrev(str1);<br /> if (!strcmp(str1,str)) if(issushu(atol(str)))<br /> data[count ++] = atol(str);//printf("%ld/t",atol(str)),data[count ++] = atol(str); </p> <p> memset(str,NULL,sizeof(str));<br /> memset(str1,NULL,sizeof(str1));<br /> }<br /> }<br /> int main()<br /> {<br /> unsigned long a,i,j,x,y;<br /> data[0] = 2,data[1] = 3,data[2] = 5,data[3] = 7,data[4] = 11;<br /> //freopen("pprime1.out","w",stdout);<br /> count = 5;<br /> int n; </p> <p> //生产所有的回文素数<br /> for(int _digit = 3; _digit <= 8;_digit+=2)<br /> {<br /> if(_digit%2==0)<br /> even_huiwen(_digit);<br /> else<br /> odd_huiwen(_digit);<br /> } </p> <p> qsort(data,count,sizeof(unsigned long ),cmp);<br /> scanf("%d",&n);<br /> while (n--)<br /> {<br /> scanf("%ld%ld",&x,&y);<br /> for (i=0;data[i] <=y&&i<=count;i++)<br /> {<br /> if (data[i]>=x)<br /> printf("%ld/n",data[i]);<br /> } </p> <p> } </p> <p> return 0; </p> <p>} </p> <p>