3.18 括号配对问题 约数的个数 质因数的个数

#include<iostream>
#include<string>
#include<stack>
using namespace std;
int main()
{
	string str;
	cin >> str;
	stack<char> s;
	for (auto a : str)
	{
		if (a == '[' || a == '(')
		{
			s.push(a);
		}
		if (a == ']' )
		{
			if (s.size() == 0) 
			{
				cout << "false";
				return 0;
			}
			else 
			{
				auto x=s.top();
				if (x == '[') 
				{
					s.pop();
				}
				else 
				{
					cout << "false";
					return 0;
				}
			}

		}
		if (a == ')')
		{
			if (s.size() == 0)
			{
				cout << "false";
				return 0;
			}
			else
			{
				auto x = s.top();
				if (x == '(')
				{
					s.pop();
				}
				else
				{
					cout << "false";
					return 0;
				}
			}

		}
	}
	if (s.size() == 0)
	{
		cout << "true";
	}
	else {
		cout << "false";
	}
	system("pause");
}

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
	int n;
	cin >> n;
	while (n--)
	{
		int x;
		cin >> x;
		int i = 1;
		int c = 0;
		for (; i < sqrt(x); i++)
		{
			if (x%i == 0) {
				
				c+=2;
			}
		}
		i = sqrt(x);
		if(i*i == x)
		{
			c++;
		}
		cout << c << endl;
	}
	system("pause");
}

#include <iostream>
#include <cmath>
using namespace std;

int main() {
	long N = 100;
	while (cin >> N)
	{
		long count = 0;
		for (long j = 2; j <= sqrt(N); j++)
		{
			while (N%j == 0)
			{
				N = N / j;
				count++;
			}
			if (N == 1)
				break;
		}
		if (N>1)
			count++;
		cout << count << endl;
	}
	return 0;
}