ADmark42 @ 2023-10-31 19:54:45
#include <stdio.h>
#include <stdbool.h>
#include <math.h>
bool zhi(int a) {
if (a <= 1 || a % 2 == 0)
return false;
for (int i = 3; i <= sqrt(a); i += 2) {
if (a % i == 0) {
return false;
}
}
return true;
}
bool hui(int a) {
int g[10], i = 0;
while (a > 0) {
g[i] = a % 10;
a /= 10;
i++;
}
for (int j = 0; j < i; j++)
if (g[j] != g[i - j - 1]) {
return false;
}
return true;
}
int main() {
int a, b;
scanf("%d %d", &a, &b);
for (int i = a; i <= b; i ++) {
if (zhi(i) == true && hui(i) == true) {
printf("%d\n", i);
}
}
}
by lym12 @ 2023-10-31 20:05:40
质数判断炸了,用埃拉托尼斯筛法,快一点,可以自行了解 @ADmark42
by Custlo0793 @ 2023-10-31 20:07:45
TwistZz 好评。
by ADmark42 @ 2023-11-01 12:54:25
@Mayile1022 ok谢谢佬
by ADmark42 @ 2023-11-01 12:54:51
@Cust10 好好好