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…an, 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…an <=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
 
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HDU 4455 Substrings[多重dp]

HDU 4455 Substrings[多重dp]

#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 ;
}
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