编程基础07

多层枚举嵌套

没什么思路先进行暴力搜索

#include<iostream>

using namespace std;
// 多层嵌套枚举

int main()
{
// 1.两个骰子，求所有排列方案

for (int i = 1; i <= 6; i++)
	{
		for (int j = 1; j <= 6; j++){
            cout << "(" << i << "," << j << ")";
        }
    cout << endl;
}



// 2.枚举2024年的每一天

int months[13] = { 0, 31, 28, 31, 30, 31, 30 ,31, 31, 30, 31, 30, 31 };
for (int i = 1; i <= 12; i++){
    for (int j = 1; j <= months[i]; j++){
        cout << i << "月" << j << "号 ";
    }
    cout << endl;
}


// 3.三位数，数位每一位不超过n且不相等，而且该三位数是奇数

int n = 7;

for (int i = 100; i <= 999; i++){// 条件
    // a b c
    //枚举百位
    for (int i = 1; i <= n; i++){
        // 枚举十位
        for (int j = 0; j <= n; j++){
            // 枚举个位
            if (i == j) continue; // 跳过当前循环，继续下一次循环
            for (int k = 1; k <= n; k += 2)
            {
                if (i != k && j != k) cout << i * 100 + j * 10 + k << endl;
            }
        }
    }
    return 0;
}

作业

679 计算自己活了多少天

#include<iostream>
using namespace std;

int months[13] = { 0, 31, 28, 31, 30, 31, 30 ,31, 31, 30, 31, 30, 31 };

int addOne(int year)
{
	if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) return 1;
	return 0;
}

int func(int year, int month, int day)
{
	int days = 0;
	for (int i = 1; i < month; i++)
	{
		days += months[i];
	}
	if (month > 2)
	{
		days += addOne(year);
	}
	days += day;
	return days;
}

int main()
{
	// 1.定义变量，输入
	int birthyear, birthmonth, birthday;
	int nowyear, nowmonth, nowday;
	cin >> birthyear >> birthmonth >> birthday;
	cin >> nowyear >> nowmonth >> nowday;

	// 2.计算整年的天数
	int days = 0;
	for (int i = birthyear; i < nowyear; i++)
	{
		// 1. 365
		// 2. 闰年+1
		days += 365 + addOne(i);
	}

	// 3.减去出生那年的天数
	days -= func(birthyear, birthmonth, birthday);

	// 4.加上现在这年的天数
	days += func(nowyear, nowmonth, nowday);
	cout << days << endl;
	return 0;
}

1601 求正整数2和n之间的完全数

#include<iostream>
using namespace std;

int check(int i)
{
	// 判断是否是完全数
	int sum = 0;
	for (int j = 1; j < i; j++)
	{
		if (i % j == 0)
		{
			sum += j;
		}
	}
	return sum == i;
}

int main()
{
	int n;
	cin >> n;
	for (int i = 2; i <= n; i++)
	{
		if (check(i))
		{
			cout << i << endl;
		}
	}
	return 0;
}

1604 亲和数

#include<iostream>
using namespace std;

int fac_sum(int x)
{
	int sum = 0;
	for (int i = 1; i < x; i++)
	{
		if (x % i == 0)
		{
			sum += i;
		}
	}
	return sum;
}

int main()
{
	for (int a = 2;; a++)
	{
		int b = fac_sum(a);
		if (fac_sum(b) == a && a != b)
		{
			cout << a << " " << b << endl;
			return 0;
		}
	}
	return 0;
}