今天刷 堆

 1 #include<iostream>
 2 #include<cstring>
 3 #include<cstdio>
 4 using namespace std;
 5 int a[110],n;
 6 int main()
 7 {
 8     scanf("%d",&n);
 9     for(int i=1;i<=n;i++)
10       scanf("%d",&a[i]);
11     for(int i=1;i<=n;i++)
12     {
13         if(i*2<=n){
14             if(a[i*2]>=a[i]){
15                 printf("No\n");return 0;
16             }
17         }
18         if(i*2+1<=n){
19             if(a[i*2+1]>=a[i]){
20                 printf("No\n");return 0;
21             }
22         }
23     }
24     printf("Yes\n");
25     return 0;
26 }