Day6上午解题

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<cmath>
 5 #include<queue>
 6 #include<algorithm>
 7 #define LL long long 
 8 using namespace std;
 9 const int MAXN=1e6+10;
10 const int INF=0x7fffff;
11 inline int read()
12 {
13     char c=getchar();int flag=1,x=0;
14     while(c<'0'||c>'9')    {if(c=='-')    flag=-1;c=getchar();}
15     while(c>='0'&&c<='9')     x=x*10+c-48,c=getchar();return x*flag;
16 }
17 int n;
18 int a[MAXN];
19 int now=0;
20 int mon[MAXN];
21 int main()
22 {
23 //    freopen("book.in","r",stdin);
24 //    freopen("book.out","w",stdout);
25     n=read();
26     for(int i=1;i<=n;i++)    a[i]=read();
27     for(int i=1;i<=n;i++)
28     {
29         if(a[i]==5)    mon[5]++;
30         if(a[i]==10)
31         {
32             if(mon[5]==0){printf("NO");return 0;}
33             else mon[5]--,mon[10]++;
34         }
35         if(a[i]==20)
36         {
37             if((mon[5]<1||mon[10]<1)&&(mon[5]<3))    {printf("NO");return 0;}
38             else 
39             {
40                 if(mon[10]>=1)
41                 mon[5]--,mon[10]--;
42                 else 
43                 mon[5]=mon[5]-3;
44             }
45         }
46     }
47     printf("YES");
48     return 0;
49 }
50 
51 /*
52 4
53 5 5 10 20  //YES
54 3
55 10 5 5 //NO 
56 
57 2
58 5 20//NO
59 
60 4
61 5 5 10 10 5 5 5 20//YES
62 */