codeforces180E_尺取法

http://codeforces.com/problemset/problem/180/E

题意：给你n个数 m种颜色 最多可以删k个数  问你最长连续颜色相同的序列长度是多少

 1 #include <algorithm>
 2 #include <iostream>
 3 #include <cstring>
 4 #include <cstdlib>
 5 #include <cstdio>
 6 #include <vector>
 7 #include <ctime>
 8 #include <queue>
 9 #include <list>
10 #include <set>
11 #include <map>
12 using namespace std;
13 #define INF 0x3f3f3f3f
14
15 vector <int> num[100010];
16 int main()
17 {
18     int n, m, k;
19     scanf("%d %d %d", &n, &m, &k);
20     int x;
21     for(int i = 1; i <= n; i++)
22     {
23         scanf("%d", &x);
24         num[x].push_back(i);
25     }
26     int res = 1;
27     for(int i = 1; i <= m; i++)
28     {
29         int te = 0, l = 0;
30         for(int j = 1; j < num[i].size(); j++)
31         {
32             te += num[i][j] - num[i][j - 1] - 1;
33             if(te > k)
34             {
35                 te -= num[i][j] - num[i][j - 1] - 1;
36                 res = max(res, num[i][j - 1] - num[i][l] + 1 - te);
37                 te += num[i][j] - num[i][j - 1] - 1;
38                 for(int l1 = l + 1; l1 <= j; l1++){
39                     te -= num[i][l1] - num[i][l1 - 1] - 1;
40                     if(te <= k)
41                     {
42                         l = l1;
43                         break;
44                     }
45                 }
46             }
47             else if(j == num[i].size() - 1 && te <= k)
48             {
49                 res = max(res, num[i][j] - num[i][l] + 1 - te);
50             }
51         }
52     }
53     printf("%d\n", res);
54     return 0;
55 }