HDU 4455 Substrings[多重dp]

Substrings

Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 3269    Accepted Submission(s): 999

Problem Description

XXX has an array of length n. XXX wants to know that, for a given w, what is the sum of the distinct elements’ number in all substrings of length w. For example, the array is { 1 1 2 3 4 4 5 } When w = 3, there are five substrings of length 3. They are (1,1,2),(1,2,3),(2,3,4),(3,4,4),(4,4,5)
The distinct elements’ number of those five substrings are 2,3,3,2,2.
So the sum of the distinct elements’ number should be 2+3+3+2+2 = 12

 

Input

There are several test cases.
Each test case starts with a positive integer n, the array length. The next line consists of n integers a₁,a₂…a_n, representing the elements of the array.
Then there is a line with an integer Q, the number of queries. At last Q lines follow, each contains one integer w, the substring length of query. The input data ends with n = 0 For all cases, 0<w<=n<=10⁶, 0<=Q<=10⁴, 0<= a₁,a₂…a_n <=10⁶

 

Output

For each test case, your program should output exactly Q lines, the sum of the distinct number in all substrings of length w for each query.

 

Sample Input

7
1 1 2 3 4 4 5
3
1
2
3
0

 

Sample Output

7
10
12

 

Source

2012 Asia Hangzhou Regional Contest

 

Recommend

#include<cstdio>
#include<cstring>
using namespace std;
const int N=1e6+;
int n,num[N];
int cx[N],add[N],lnc[N];
long long f[N];
void Discretization(){
    memset(cx,,sizeof cx);
    memset(lnc,,sizeof lnc);
    for(int i=;i<=n;i++){
        if(!cx[num[n-i+]]){
            cx[num[n-i+]]=;
            lnc[i]=lnc[i-]+;
        }
        else{
            lnc[i]=lnc[i-];
        }
    }
    memset(cx,,sizeof cx);
    memset(add,,sizeof add);
    for(int i=;i<=n;i++){
        add[i-cx[num[i]]]++;
        cx[num[i]]=i;
    }
}
void DynamicProgramming(){
    memset(f,,sizeof f);
    f[]=n;int delta=n;
    for(int i=;i<=n;i++){
        f[i]=f[i-]-lnc[i-];
        delta-=add[i-];
        f[i]+=delta;
    }
}
void Solution(){
    int Q,x;
    for(scanf("%d",&Q);Q--;) scanf("%d",&x),printf("%lld\n",f[x]);
}
int main(){
    while((~scanf("%d",&n))&&n){
        for(int i=;i<=n;i++) scanf("%d",&num[i]);
        Discretization();
        DynamicProgramming();
        Solution();
    }
    return ;
}