1059. Prime Factors (25)-PAT甲级真题(素数表的建立)

Given any positive integer N, you are supposed to find all of its prime factors, and write them in the format N = p1^k1 * p2^k2 *…*pm^km.

Input Specification:

Each input file contains one test case which gives a positive integer N in the range of long int.

Output Specification:

Factor N in the format N = p1^k1 * p2^k2 *…*pm^km, where pi’s are prime factors of N in increasing order, and the exponent ki is the number of pi — hence when there is only one pi, ki is 1 and must NOT be printed out.

Sample Input:
97532468
Sample Output:
97532468=2^2*11*17*101*1291
题目大意:给出一个整数,按照从小到大的顺序输出其分解为质因数的乘法算式
分析:根号int的最大值不超过50000,先建立个50000以内的素数表,然后从2开始一直判断是否为它的素数,如果是就将a=a/i继续判断i是否为a的素数,判断完成后输出这个素数因子和个数,用state判断是否输入过因子,输入过就要再前面输出“*”