【单调队列】HDU_3706_Second My Problem First

Second My Problem First

Time Limit: 12000/4000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 1931    Accepted Submission(s): 734

Problem Description

Give you three integers n, A and B.
Then we define S_i = Aⁱ mod B and T_i = Min{ S_k | i-A <= k <= i, k >= 1}
Your task is to calculate the product of T_i (1 <= i <= n) mod B.

 

Input

Each line will contain three integers n(1 <= n <= 10⁷),A and B(1 <= A, B <= 2³¹-1).
Process to end of file.

 

Output

For each case, output the answer in a single line.

 

Sample Input

1 2 32 3 43 4 54 5 65 6 7

 

Sample Output

23456

 

Author

WhereIsHeroFrom@HDU

 

Source

HDOJ 5th Anniversary Contest

 

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lcy

#include <cstdio>#include <cstring>#include <cmath>#include <algorithm>using namespace std;typedef long long LL;const int maxn=1e6+1;LL s[maxn],q[maxn],b;int main(){    LL n, a;    while(~scanf("%lld%lld%lld",&n,&a,&b)){        LL front=0,rear=0;        LL ans=1,x=1;        for(LL i=1;i<=n;i++){            LL l=max(1LL,i-a);            x=x*a%b;            while(front<rear&&x<s[rear-1])                rear--;            s[rear]=x;            q[rear++]=i;            while(front<rear&&l>q[front])                front++;            ans=ans*s[front]%b;        }        printf("%lld\n",ans);    }    return 0;}