题目传送门
1 /*
2 贪心 + 模拟：首先，如果蜡烛的燃烧时间小于最少需要点燃的蜡烛数一定是-1(蜡烛是1秒点一支)，
3 num[g[i]]记录每个鬼访问时已点燃的蜡烛数，若不够，tmp为还需要的蜡烛数，
4 然后接下来的t秒需要的蜡烛都燃烧着，超过t秒，每减少一秒灭一支蜡烛，好！！！
5 详细解释：http://blog.csdn.net/kalilili/article/details/43412385
6 */
7 #include <cstdio>
8 #include <algorithm>
9 #include <cmath>
10 #include <cstring>
11 #include <string>
12 using namespace std;
13
14 const int MAXN = 1e3 + 10;
15 const int MAXG = 300 + 10;
16 const int INF = 0x3f3f3f3f;
17 int g[MAXG];
18 int num[MAXN];
19
20 int main(void) //Codeforces Round #288 (Div. 2) C. Anya and Ghosts
21 {
22 #ifndef ONLINE_JUDGE
23 freopen ("C.in", "r", stdin);
24 #endif
25
26 int m, t, r;
27
28 scanf ("%d%d%d", &m, &t, &r);
29 for (int i=1; i<=m; ++i)
30 scanf ("%d", &g[i]);
31
32 if (t < r)
33 {
34 puts ("-1"); return 0;
35 }
36 int ans = 0;
37 for (int i=1; i<=m; ++i)
38 {
39 if (num[g[i]] < r)
40 {
41 int tmp = r - num[g[i]];
42 ans += tmp;
43 for (int j=g[i]+1; j<=g[i]-tmp+t; ++j) num[j] += tmp;
44 for (int j=g[i]-tmp+t+1; j<=g[i]+t-1; ++j) num[j] += (--tmp);
45 }
46 }
47
48 printf ("%d\n", ans);
49
50 return 0;
51 }