C :

#include <stdio.h>
int main()
{
    int t;
    int ch[1000010];
    scanf("%d", &t);
    for(int i = 0; i < t; i++)
    {
        scanf("%d", &ch[i]);
    }
    int Y25 = 0, Y50 = 0;
    for(int i = 0; i < t; i++ )
    {
        if(ch[i] == 25)
        {
            Y25++;
        }
        else if(ch[i] == 50)
        {
            if(Y25 > 0)
            {
                Y25--;
                Y50++;
            }
            else
            {
                printf("NO");
                return 0;
            }
        }
        else
        {
            if(Y50 > 0 && Y25 > 0)
            {
                Y50--;
                Y25--;
            } 
            else if(Y25 >= 3)
            {
                Y25 -= 3;
            }
             else
            {
                printf("NO");
                return 0;
            }
        }
    }
    if(Y25 >= 0 && Y50 >= 0) 
    {
        printf("YES");
    } 
    else 
    {
        printf("NO");
    }
    return 0;
}

C++ :

#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N=1e6+10;
typedef pair<int,int> PII;
typedef priority_queue<int , vector<int>, greater<int>> minqueue;  //从小到大 queue
typedef priority_queue<int, vector<int>, less<int>> maxqueue;      //从大到小 queue

int gcd(int a, int b){  //最大公因数 
    return b ? gcd(b, a % b) : a;
}

int lcm(int a, int b){ //最小公倍数 
    return a * b / __gcd(a, b);
}

int qmi(int base, int power, int p)  //快速幂求余 
{
	int result = 1;   
	while (power > 0)           
	{
		if (power & 1)         							
			result = result * base % p;   
		base = base * base % p ;       						
		power >>= 1;         						
	}
	return result % p;       
}

int a[N],x25=0,x50=0;

void solve()
{
	int n;
	cin>>n;
	for(int i=0;i<n;i++) cin>>a[i];
	for(int i=0;i<n;i++){
		if(a[i]==25) x25++;
		else if(a[i]==50){
			x25--;
			x50++;
		}
		else{
			if(x25>0&&x50>0){
				x25--;
				x50--;
			}
			else x25-=3;
		}
		if(x25<0||x50<0){
			cout<<"NO"<<'\n';
			return;
		}
	}
	cout<<"YES"<<'\n';
}

signed main()
{
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	int t;
	t=1;
	//cin>>t; 
	while(t--)     
	{
		solve();
	}
	return 0;
}