编写题解 2950: 素数回文数的个数

解题思路:

注意事项:

参考代码:

#include<stdio.h>

#include<string.h>

int main() {

int a, i, j, sum = 0, b[1000], k = 0;

int ge, shi, bai;

scanf("%d", &a);

for (i = 11; i <= a; i++) {

for (j = 2; j <= i; j++) {

if (i % j == 0)break;

}

if (i == j){b[k++]=i;}

}

for (i = 0; i < k; i++) {

ge = b[i] % 10;

shi = b[i] % 100 / 10;

bai = b[i] / 100;

if (ge == shi && (bai == 0))sum++;

else if (ge == bai)sum++;

}

printf("%d", sum);

return 0;

}