DZY loves Fast Fourier Transformation, and he enjoys using it.
Fast Fourier Transformation is an algorithm used to calculate convolution. Specifically, if a, b and c are sequences with length n, which are indexed from 0 to n - 1, and
We can calculate c fast using Fast Fourier Transformation.
DZY made a little change on this formula. Now
To make things easier, a is a permutation of integers from 1 to n, and b is a sequence only containing 0 and 1. Given a and b, DZY needs your help to calculate c.
Because he is naughty, DZY provides a special way to get a and b. What you need is only three integers n, d, x. After getting them, use the code below to generate a and b.
//x is 64-bit variable;function getNextX() { x = (x * 37 + 10007) % 1000000007; return x;}function initAB() { for(i = 0; i < n; i = i + 1){ a[i] = i + 1; } for(i = 0; i < n; i = i + 1){ swap(a[i], a[getNextX() % (i + 1)]); } for(i = 0; i < n; i = i + 1){ if (i < d) b[i] = 1; else b[i] = 0; } for(i = 0; i < n; i = i + 1){ swap(b[i], b[getNextX() % (i + 1)]); }}
Operation x % y denotes remainder after division x by y. Function swap(x, y) swaps two values x and y.
The only line of input contains three space-separated integers n, d, x (1 ≤ d ≤ n ≤ 100000; 0 ≤ x ≤ 1000000006). Because DZY is naughty, x can't be equal to 27777500.
Output n lines, the i-th line should contain an integer ci - 1.
3 1 1
132
5 4 2
22455
5 4 3
55554
In the first sample, a is [1 3 2], b is [1 0 0], so c0 = max(1·1) = 1, c1 = max(1·0, 3·1) = 3, c2 = max(1·0, 3·0, 2·1) = 2.
In the second sample, a is [2 1 4 5 3], b is [1 1 1 0 1].
In the third sample, a is [5 2 1 4 3], b is [1 1 1 1 0].
这题解法‘朴素’得难以置信
转载自:
Firstly, you should notice that A, B are given randomly.
Then there're many ways to solve this problem, I just introduce one of them.
This algorithm can get Ci one by one. Firstly, choose an s. Then check if Ci equals to n, n - 1, n - 2... n - s + 1. If none of is the answer, just calculate Ci by brute force.
The excepted time complexity to calculate Ci - 1 is around
where .
Just choose an s to make the formula as small as possible. The worst excepted number of operations is around tens of million.
对于每次询问:
先暴力枚举,看看答案在不在[n-s+1,n]中
否则暴力。
复杂度=O(s+(tot'0'/i)^s*tot'1')
(tot'0'/i)^s表示[n,n-s+1]中没有答案
#include#include #include #include #include #include #include #include #include using namespace std;#define For(i,n) for(int i=1;i<=n;i++)#define Fork(i,k,n) for(int i=k;i<=n;i++)#define Rep(i,n) for(int i=0;i =0;i--)#define Forp(x) for(int p=pre[x];p;p=next[p])#define Lson (x<<1)#define Rson ((x<<1)+1)#define MEM(a) memset(a,0,sizeof(a));#define MEMI(a) memset(a,127,sizeof(a));#define MEMi(a) memset(a,128,sizeof(a));#define INF (2139062143)#define F (100000007)#define MAXN (100000+10)#define MAXX (1000000006+1)#define N_MAXX (27777500)long long mul(long long a,long long b){return (a*b)%F;}long long add(long long a,long long b){return (a+b)%F;}long long sub(long long a,long long b){return (a-b+(a-b)/F*F+F)%F;}typedef long long ll;ll n,d,x;int i,a[MAXN],b[MAXN];//x is 64-bit variable;ll getNextX() { x = (x * 37 + 10007) % 1000000007; return x;}void initAB() { for(i = 0; i < n; i = i + 1){ a[i] = i + 1; } for(i = 0; i < n; i = i + 1){ swap(a[i], a[getNextX() % (i + 1)]); } for(i = 0; i < n; i = i + 1){ if (i < d) b[i] = 1; else b[i] = 0; } for(i = 0; i < n; i = i + 1){ swap(b[i], b[getNextX() % (i + 1)]); }}int q[MAXN]={0},h[MAXN]={0};int main(){// freopen("FFT.in","r",stdin);// freopen("FFT.out","w",stdout); cin>>n>>d>>x; initAB(); Rep(i,n) if (b[i]) q[++q[0]]=i; Rep(i,n) h[a[i]]=i; // Rep(i,n) cout< <<' ';cout< i) break; ans=max(ans,a[i-t]*b[t]); } } printf("%d\n",ans); } return 0;}
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