题目：https://pintia.cn/problem-sets/994805342720868352/problems/994805370650738688

这题与素数没啥太大关系，一开始想多了，事实只要求出第一个数字和实际长度就行了

代码

  1. #include<vector>
  2. #include<algorithm>
  3. #include<cstdio>
  4. #include<cmath>
  5. #include<iostream>
  6. using namespace std;
  7. typedef long long LL;
  9. int main(){
  10.     LL n;
  11.     LL ans_first = 0, ans_len = 0;
  12.     scanf("%lld",&n);
  13.     LL sqr = (LL)sqrt(1.0 * n);
  14.     for(LL i = 2; i <= sqr; i++){
  15.         LL temp = 1;
  16.         for(LL j = i; j <= sqr; j++){
  17.             temp *= j;
  18.             if(n % temp != 0) break;
  19.             if(j - i + 1 > ans_len){
  20.                 ans_first = i;
  21.                 ans_len = j - i + 1;
  22.             }
  23.         }
  24.     }
  25.     if(ans_len == 0) {
  26.         printf("1\n%lld",n);
  27.     }
  28.     else {
  29.         printf("%lld\n",ans_len);
  30.         for(LL i = ans_first; i < ans_first + ans_len; i++){
  31.             printf("%lld",i);
  32.             if( i != ans_first + ans_len - 1) printf("*");
  33.         }
  34.     }
  35.     return 0;
  36. }