BZOJ2259 [Oibh]新型计算机

话说hzwer你在坑爹？、、、

我按照你的建图交了上去，发现WA。

开始检查= =。。。过了好久，突然觉得画风不对。。。hzwer您建图错了啊！！！

后来看了看zyk的终于知道了怎么回事>_<

 1 /**************************************************************
 2     Problem: 2259
 3     User: rausen
 4     Language: C++
 5     Result: Accepted
 6     Time:3220 ms
 7     Memory:52884 kb
 8 ****************************************************************/
 9
10 #include <cstdio>
11 #include <algorithm>
12 #include <cstring>
13 #include <queue>
14
15 using namespace std;
16 typedef long long ll;
17 const int N = 1000005;
18 const int M = 3000005;
19
20 int n, tot;
21 int dis[N], first[N];
22 bool vis[N], pre[N], nxt[N];
23
24 struct edges {
25     int next, to, v;
26     edges() {}
27     edges(int _n, int _t, int _v) : next(_n), to(_t), v(_v) {}
28 } e[M];
29
30 struct heap_node {
31     int v, to;
32     heap_node() {}
33     heap_node(int _v, int _to) : v(_v), to(_to) {}
34
35     inline bool operator < (const heap_node &b) const {
36         return v > b.v;
37     }
38 };
39
40 priority_queue <heap_node> h;
41
42 inline int read() {
43     int x = 0;
44     char ch = getchar();
45     while (ch < ‘0‘ || ‘9‘ < ch)
46         ch = getchar();
47     while (‘0‘ <= ch && ch <= ‘9‘) {
48         x = x * 10 + ch - ‘0‘;
49         ch = getchar();
50     }
51     return x;
52 }
53
54 void add_edge(int x, int y, int z) {
55     e[++tot] = edges(first[x], y, z);
56     first[x] = tot;
57 }
58
59 inline void add_to_heap(const int p) {
60     for (int x = first[p]; x; x = e[x].next)
61         if (dis[e[x].to] == -1)
62             h.push(heap_node(e[x].v + dis[p], e[x].to));
63 }
64
65 void Dijkstra(int S) {
66     memset(dis, -1, sizeof(dis));
67     while (!h.empty()) h.pop();
68     dis[S] = 0, add_to_heap(S);
69     int p;
70     while (!h.empty()) {
71         if (dis[h.top().to] != -1) {
72             h.pop();
73             continue;
74         }
75         p = h.top().to;
76         dis[p] = h.top().v;
77         h.pop();
78         add_to_heap(p);
79     }
80 }
81
82 int main() {
83     int i, j, x;
84     n = read();
85     for (i = 1; i <= n; ++i) {
86         x = read();
87         for (j = i + 1; j <= min(i + x + 1, n) && !pre[j]; ++j)
88             pre[j] = 1, add_edge(j, j - 1, 1);
89         for (j = i + x + 1; j <= n && !nxt[j]; ++j)
90             nxt[j] = 1, add_edge(j, j + 1, 1);
91         if (i + x <= n) add_edge(i, i + x + 1, 0);
92         else add_edge(i, n + 1, i + x - n);
93     }
94     Dijkstra(1);
95     printf("%d\n", dis[n + 1]);
96     return 0;
97 }