https://note.ms/hjcz

#include <bits/stdc++.h>
using namespace std;
#define For(i,x,y) for (int i = x;i <= y; ++ i)
#define Dor(i,x,y) for (int i = x;i >= y; -- i)
#define in push_back
#define out pop_back
typedef double db;
typedef char ch;
typedef string str;
typedef float fl;
typedef signed sig;
typedef long long ll;
typedef bool bo;
typedef void vo;
typedef vector<int> vec;
typedef queue<int> que;//定义队列 
/*
push()  插入
front() 访问队首元素 
pop()   删除队首
empty() 检查队列是否为空
size()  获取队列大小 
*/
priority_queue<int,vec,greater<int> > q;//定义小根堆 
ll gcd (ll x,ll y)
{
	if (y == 0) return x;
	return gcd (y,x % y);
}
ll lcm (ll x,ll y)
{
	return x / gcd (x,y) * y;
}
bo ss(int x)
{
	if (x < 2) return false;
	for (int i = 2;i * i <= x; ++ i)
	if (x % i == 0) return false;
	return true;
}

str pd(str m1,str m2)
{
	int l1 = m1.size(),l2 = m2.size();
	if (l1 > l2) return m1;
	if (l1 < l2) return m2;
	if (m1 >= m2) return m1;
	return m2;
}
vec add (vec &A,vec &B)
{
	if (A.size() < B.size()) return add (B,A);
	vec C;
	int t = 0;
	For(i,0,A.size() - 1)
	{
		t += A[i];
		if (i < B.size()) t += B[i];
		C.in (t % 10); 
		t /= 10;
	}
	if (t) C.in (t);
	return C;
}//a+b
vec sub (vec &A,vec &B)
{
	vec C;
	for(int i = 0,t = 0;i < A.size(); ++ i)
	{
		t = A[i] - t;
		if (i < B.size()) t -= B[i];
		C.in ((t + 10) % 10);
		if (t < 0) t = 1;
		else t = 0;
	}
	while (C.size() > 1 && C.back() == 0) C.out ();
	return C;
}//a-b
vo quick_sort(int a[],int l,int r)
{
	if (l >= r) return ;
	int i = l - 1,j = r + 1,x = a[l];
	while (i < j)
	{
		do ++ i;
		while (a[i] < x);
		do -- j;
		while (a[j] > x);
		if (i < j) swap (a[i],a[j]);
		else break;
	}
	quick_sort(a,l,j),quick_sort(a,j + 1,r);
}
vo merge_sort(int q[],int l,int r)
{
	if (l >= r) return ;
	int mid = l + r >> 1;
	merge_sort (q,l,mid);
	merge_sort (q,mid + 1,r);
	int k = 0,i = l,j = mid + 1;
	while (i <= mid && j <= r)
	if (q[i] < q[j]) tmp[k ++] = q[i ++];
	else tmp[k ++] = q[j ++];
	while (i <= mid) tmp[k ++] = q[i ++];
	while (j <= r) tmp[k ++] = q[j ++];
	for (i = l,j = 0;i <= r;++ i, ++ j) q[i] = tmp[j];
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0),cout.tie(0);

    
    for (int i = 2;i * i <= n; ++ i)
	{
		if (p[i] == 0)
		for (int j = i * i;j <= n;j += i) p[j] = 1;
	}
	for (int i = 2;i <= n; ++ i) if (p[i] == 0) a[++ k] = i;//素数表
    
    
        
    for (int i = 1;i <= n; ++ i)
	{
		int x;
		cin >> x;
		q.push(x);//把元素塞入数组 
	}
	while (q.size() > 0)
	{
		cout << q.top() << " ";//输出最小值 
		q.pop();//弹出最小值 
	}




    Dor(i,s1.size() - 1,0) a.push_back (s1[i] - '0');
	Dor(i,s2.size() - 1,0) b.push_back (s2[i] - '0');
	c = add(a,b);




    Dor(i,s1.size() - 1,0) a.push_back (s1[i] - '0');
	Dor(i,s2.size() - 1,0) b.push_back (s2[i] - '0');
	c = sub(a,b);
	return 0;
}

手搓推排序：

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef string sb;
ll m;
priority_queue<int,vector<int>,greater<int> >q;
int main() {
	cin>>m;
	for(int i=1;i<=m;i++) {
		int x;
		cin>>x;
		q.push(x);
	}
	while(q.size()>0) {
		cout<<q.top()<<" ";
		q.pop();
	}
	return 0;
}

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define For(i,a,b) for(int i=a;i<=b;i++)
ll n;
char a[100],b[100];
void dfs(int k) {
	if(k>n) {
		For(i,1,n) cout<<b[i];
		cout<<endl;
		return ;
	}
	For(i,1,4) {
		if(k==n&&a[i]==b[2]) continue;
		if(a[i]!=b[1]&&a[i]!=b[k-1]) {
			b[k]=a[i];
			dfs(k+1);
		}
	}
}
int main() {
	cin>>n;
	a[1]='r';
	a[2]='g';
	a[3]='b';
	a[4]='y';
	for(int i=1; i<=4; i++) {
		b[1]=a[i];
		dfs(2);
	}
}

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define For(i, a, b) for(ll i = a; i <= b; ++ i)
ll n, x, k, a[1000005], t, s;
int main() {
	cin>>n;
	x = sqrt(n);
	For(i, 1, x) 
		if(n % i == 0) {
			if(i * i != n)	a[++ k] = i, a[++ k] = n / i;
			  else a[++ k] = i;
		}
	For(i, 1, k)
		For(j, 1, k) {
			t = n / a[i] / a[j];
			if(a[i] * a[j] * t == n) ++ s;
		}
	cout << s;
	return 0;
}