暑期训练狂刷系列——Foj 1894 志愿者选拔 （单调队列）

 1 #include <cstdio>
 2 #include <cstring>
 3 using namespace std;
 4 const int maxn = 1000005;
 5 
 6 struct node
 7 {
 8     int index, val;
 9 }Q[maxn];
10 
11 int main ()
12 {
13     int t;
14     char str[10];
15     scanf ("%d", &t);
16     while (t --)
17     {
18         int head, last, num, cur, x;
19         scanf ("%s", &str);
20         head = last = x = 0;
21         cur = -1;
22         while (scanf ("%s", str), strcmp(str, "END"))
23         {
24             if (str[0] == ‘C‘)
25             {
26                 scanf ("%s %d", str, &num);
27                 //当前位置不在队首，进队元素优先级高于当前元素
28                 while (head<=cur && Q[cur].val<num)
29                     cur --;
30                 Q[++cur].index = x++;
31                 Q[cur].val = num;
32             }
33             else if (str[0] == ‘Q‘)
34             {//队首元素已经出队，就向下遍历次优元素
35                 while (head<=cur && Q[head].index<last)
36                     head ++;
37                 if (head > cur)
38                     printf ("-1\n");
39                 else
40                     printf ("%d\n", Q[head].val);
41             }
42             else
43                 last ++;//出队元素数目
44         }
45     }
46     return 0;
47 }