1059 Prime Factors (25 分)

1059 Prime Factors (25 分)

Sample Input:

97532468

Sample Output:

97532468=2^2*11*17*101*1291

#include 
#include 
#include 
#include 
using namespace std;
const int maxn = 100010;

bool isPrime(int n) {
	if (n <= 1) return false;
	int Sqrt = (int)sqrt(1.0 * n);
	for (int i = 2;i <= Sqrt;i++) {
		if (n % i == 0) return false;
	}
	return true;
}
int prime[maxn], pNum = 0;
void Find_Prime() {
	for (int i = 1;i < maxn;i++) {
		if (isPrime(i) == true) {
			prime[pNum++] = i;
		}
	}
}
struct factor {
	int x, cnt;
}fac[10];
int main() {
	Find_Prime();
	int n, num = 0;
	cin >> n;
	if (n == 1) cout << "1=1";
	else {
		cout << n << "=";
		int Sqrt = (int)sqrt(1.0 * n);
		//枚举根号n以内的质因数
		for (int i = 0;i < pNum && prime[i] <= Sqrt;i++) {
			if (n % prime[i] == 0) {
				fac[num].x = prime[i];
				fac[num].cnt = 0;
				while (n % prime[i] == 0) {
					fac[num].cnt++;
					n /= prime[i];
				}
				num++;
			}
			if (n == 1) break;
		}
		if (n != 1) {
			fac[num].x = n;
			fac[num++].cnt = 1;
		}
		//按格式输出结果
		for (int i = 0;i < num;i++) {
			if (i > 0) printf("*");
			cout << fac[i].x;
			if (fac[i].cnt > 1) {
				cout << "^" << fac[i].cnt;
			}
		}
	}
	return 0;
}