Ball

可以用dfs，不过发现用一个循环就可以搞定。

 1 #include <iostream>
 2 using namespace std;
 3 int a[11], n;
 4 int main(){
 5     cin >> n;
 6     while(n--){
 7         for(int i = 0; i < 10; i ++) cin >> a[i];
 8         int c = 0, b = 0, flag = 1;
 9         for(int i = 0; i < 10; i ++){
10             if(c > b){
11                 if(a[i] > c){
12                     c = a[i];
13                 }else if(a[i] > b){
14                     b = a[i];
15                 }else{
16                     flag = 0;
17                 }
18             }else{
19                 if(a[i] > b){
20                     b = a[i];
21                 }else if(a[i] > c){
22                     c = a[i];
23                 }else{
24                     flag = 0;
25                 }
26             }
27         }
28         if(flag) cout << "YES" << endl;
29         else cout << "NO" << endl;
30     }
31     return 0;
32 }