PAT 1059. Prime Factors

反正知道了就是知道，不知道也想不到，很快

#include <cstdio>

#include <cstdlib>

#include <vector>



using namespace std;



inline void print_prime_k(long long p, long long k) {

       printf("%lld", p);

       if (k > 1) {

          printf("^%lld", k);      

       }

}



int main() {

    long long n, on;

    scanf("%lld", &n);

    on = n;

    vector<long long> ps;

    vector<long long> count;

    

    long long i = 2;

    long long last = 0;

    while (n > 1) {

        while (n % i == 0) {

              n = n/i;

              if (i != last) {

                 ps.push_back(i);

                 count.push_back(0);

                 last = i;             

              }

              count.back()++;

        }

        i++;

    }

    

    int len = ps.size();

    if (len > 0) {

       printf("%lld=", on);

       print_prime_k(ps[0], count[0]);

    } else {

      printf("%lld=%lld", on, on);       

    }

    for (int i=1; i<len; i++) {

        printf("*");

        print_prime_k(ps[i], count[i]);

    }

    system("pause");

    return 0;    

}

考虑输入是1的情况输出要为1=1