[HDOJ5500]Reorder the Books

 1 #include <algorithm>
 2 #include <iostream>
 3 #include <iomanip>
 4 #include <cstring>
 5 #include <climits>
 6 #include <complex>
 7 #include <fstream>
 8 #include <cassert>
 9 #include <cstdio>
10 #include <bitset>
11 #include <vector>
12 #include <deque>
13 #include <queue>
14 #include <stack>
15 #include <ctime>
16 #include <set>
17 #include <map>
18 #include <cmath>
19 
20 using namespace std;
21 
22 const int maxn = 20;
23 int n;
24 int book[maxn];
25 
26 int main() {
27     int T_T;
28     scanf("%d", &T_T);
29     while(T_T--) {
30         scanf("%d", &n);
31         for(int i = 1; i <= n; i++) {
32             scanf("%d", &book[i]);
33         }
34         int cnt = n;
35         for(int i = n; i > 0; i--) {
36             if(cnt == book[i]) {
37                 cnt--;
38             }
39         }
40         printf("%d\n", cnt);
41     }
42 }