Subsequence

Time Limit: 1000ms

Memory Limit: 32768KB

This problem will be judged on 

HDU. Original ID: 

64-bit integer IO format: %I64d      Java class name: Main

 

 

There is a sequence of integers. Your task is to find the longest subsequence that satisfies the following condition: the difference between the maximum element and the minimum element of the subsequence is no smaller than m and no larger than k.

 

Input

There are multiple test cases.

For each test case, the first line has three integers, n, m and k. n is the length of the sequence and is in the range [1, 100000]. m and k are in the range [0, 1000000]. The second line has n integers, which are all in the range [0, 1000000].

Proceed to the end of file.

 

Output

For each test case, print the length of the subsequence on a single line.

 

Sample Input

5 0 01 1 1 1 15 0 31 2 3 4 5

Sample Output

54

Source

 

解题：单调队列！马丹，真蛋疼，第一次搞这个。。。。。

 

1 #include 
        
          2 #include 
         
           3 #include 
          
            4 #include 
           
             5 #include 
            
              6 #include 
             
               7 #include 
              
                8 #include 
               
                 9 #define LL long long10 #define INF 0x3f3f3f3f11 using namespace std;12 const int maxn = 100100;13 int qa[maxn],qb[maxn],h1,h2,t1,t2;14 int n,m,k,d[maxn],lst1,lst2;15 int main(){16 int i,ans;17 while(~scanf("%d %d %d",&n,&m,&k)){18 for(i = 1; i <= n; i++)19 scanf("%d",d+i);20 lst2 = lst1 = h1 = h2 = 0;21 t1 = t2 = -1;22 ans = 0;23 for(i = 1; i <= n; i++){24 while(t1 >= h1 && d[qa[t1]] <= d[i]) t1--;25 qa[++t1] = i;26 while(t2 >= h2 && d[qb[t2]] >= d[i]) t2--;27 qb[++t2] = i;28 while(d[qa[h1]] - d[qb[h2]] > k){29 if(qa[h1] < qb[h2]){30 lst1 = qa[h1++];31 }else lst2 = qb[h2++];32 }33 if(d[qa[h1]] - d[qb[h2]] >= m)34 ans = max(ans,i-max(lst1,lst2));35 }36 printf("%d\n",ans);37 }38 return 0;39 }40 /*41 5 0 042 1 1 1 1 143 5 0 344 1 2 3 4 545 */