BZOJ2096 [Poi2010]Pilots

好奇怪啊，莫名其妙的WA了好几次。。。

两个类似单调队列的东西维护就可以了

后来才发现。。。tmp忘了开始的时候赋值1了（抓狂ing）

 

 1 /**************************************************************
 2     Problem: 2096
 3     User: rausen
 4     Language: C++
 5     Result: Accepted
 6     Time:1092 ms
 7     Memory:79908 kb
 8 ****************************************************************/
 9  
10 #include <cstdio>
11 #include <algorithm>
12  
13 using namespace std;
14 const int N = 3000005;
15 const int Maxlen = 15 * N + 105;
16  
17 int n, k, ans = 1;
18 int a[N], q[2][N], l[2], r[2];
19 char buf[Maxlen], *c = buf;
20 int Len;
21  
22 inline int read() {
23     int x = 0, sgn = 1;
24     while (*c < '0' || '9' < *c) {
25             if (*c == '-') sgn = -1; 
26             ++c;
27         }
28     while ('0' <= *c && *c <= '9')
29         x = x * 10 + *c - '0', ++c;
30     return sgn * x;
31 }
32  
33 inline void pop_tail_max(int i) {
34     while (l[0] <= r[0] && a[q[0][r[0]]] <= a[i])
35         --r[0];
36     q[0][++r[0]] = i;
37 }
38  
39 inline void pop_tail_min(int i) {
40     while (l[1] <= r[1] && a[q[1][r[1]]] >= a[i])
41         --r[1];
42     q[1][++r[1]] = i;
43 }
44  
45 int main() {
46     int i, tmp;
47     Len = fread(c, 1, Maxlen, stdin);
48     buf[Len] = '\0';
49     k = read(), n = read();
50     for (i = 1; i <= n; ++i)
51         a[i] = read();
52     l[0] = l[1] = 1, r[0] = r[1] = 0;
53     for (i = tmp = 1; i <= n; ++i) {
54         pop_tail_max(i);
55         pop_tail_min(i);
56         while (a[q[0][l[0]]] - a[q[1][l[1]]] > k)
57             if (q[0][l[0]] < q[1][l[1]]) tmp = q[0][l[0]++] + 1;
58             else tmp = q[1][l[1]++] + 1;
59         ans = max(ans, i - tmp + 1);
60     }
61     printf("%d\n", ans);
62     return 0;
63 }
View Code

 

posted on 2014-11-28 23:17  Xs酱~  阅读(212)  评论(0)  编辑  收藏  举报