美素数备忘

#include<stdio.h>#include<math.h>#define maxn 1000000+1int prime[maxn];int count[maxn];bool is_beauty_prime(int n);int tot = 0;void getPrime(){    int i, j;    int tmp = int((double)sqrt(maxn) + 1);    for(i = 2; i < maxn; i++)    {        prime[i] = 1;    }    for(i = 2; i < maxn; i++)    {        if(prime[i])        {            if(i < tmp)            {                for(j = i*i; j < maxn; j+=i)                    prime[j] = 0;            }        }    }    for(i = 2; i < maxn; i++)    {        if(prime[i] && is_beauty_prime(i))        {            count[++tot] = i;        }    }}bool is_beauty_prime(int n){    int tmp = 0;    while(n)    {        tmp += n%10;        n /= 10;    }    if(prime[tmp])        return true;    return false;}int binary_search(int l, int h, int num){    while(l <= h)    {        int mid = (l+h)/2;        if(num == count[mid])            return mid;        else if(count[mid] > num)        {            h = mid-1;        }        else        {            l = mid+1;        }    }    return l;}int beauty_prime(int a, int b){    int i;    int sum = 0;    for(i = a; i <= b; i++)    {        if(prime[i])        {           if(is_beauty_prime(i))               sum++;        }    }    return sum;}int main(){    int n, a, b, i, j;    getPrime();    scanf("%d", &n);    for(i = 1; i <= n; i++)    {        int top = 0;        int down = 0;        scanf("%d %d", &a, &b);        down = binary_search(1, tot, a);        top = binary_search(1, tot, b);        if(count[top] == b)top++;        down--;        int num = top-down-1;        printf("Case #%d: %d\n", i, num);    }}