Hints of sd0061(快排思想)

Hints of sd0061

Time Limit: 5000/2500 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)
Total Submission(s): 492    Accepted Submission(s): 106

Problem Description

sd0061, the legend of Beihang University ACM-ICPC Team, retired last year leaving a group of noobs. Noobs have no idea how to deal with m coming contests.sd0061 has left a set of hints for them.

There are n noobs in the team, the i-th of which has a rating ai. sd0061 prepares one hint for each contest. The hint for the j-th contest is a number bj, which means that the noob with the (bj+1)-th lowest rating is ordained by sd0061 for the j-th contest.

The coach asks constroy to make a list of contestants. constroy looks into these hints and finds out: bi+bj≤bk is satisfied if bi≠bj, bi<bk and bj<bk.

Now, you are in charge of making the list for constroy.

 

Input

There are multiple test cases (about 10).

For each test case:

The first line contains five integers n,m,A,B,C. (1≤n≤107,1≤m≤100)

The second line contains m integers, the i-th of which is the number bi of the i-th hint. (0≤bi<n)

The n noobs' ratings are obtained by calling following function n times, the i-th result of which is ai.

unsigned x = A, y = B, z = C;
unsigned rng61() {
  unsigned t;
  x ^= x << 16;
  x ^= x >> 5;
  x ^= x << 1;
  t = x;
  x = y;
  y = z;
  z = t ^ x ^ y;
  return z;
}

 

Output

For each test case, output "Case #x: y1 y2 ⋯ ym" in one line (without quotes), where x indicates the case number starting from 1 and yi (1≤i≤m)denotes the rating of noob for the i-th contest of corresponding case.

 

Sample Input

3 3 1 1 1

0 1 2

2 2 2 2 2

1 1

 

Sample Output

Case #1: 1 1 202755

Case #2: 405510 405510

 

Source

2017 Multi-University Training Contest - Team 1

 

 

//题意: n,m,a,b,c abc为3个参数，用这些参数生成n个数，然后，求排好序后的 n 个数中，m 次查询，第 i 的数的值

 

//题解：这种数据下 10e7 ，不能直接用快排，就算快排，还是会超时，但是要利用快排的思想。因为 m 比较小，可以这样，每次快排结束后，前部分一定比分界值小或等，后半部分一定大或等，要查询第 k 大的数时，如果 k 在分界位置左边，就只排左边，在右就只排右，这样，每阶段快排省去一半区间，就行了，还wa了一发，很蛋疼，因为生成数据那部分不能直接用LL，只能用题目给的unsigned ，卡数据，很难玩那！

但是还是差点超时 2300ms ，评测机卡还有可能TLE，我擦，让我再想想怎么优化

#include <iostream>
#include <stdio.h>
#include <string.h>
using namespace std;
#define LL long long
#define MXN 10000005
#define MXM 105

int num[MXM];
LL prt[MXM];
LL data[MXN];
bool vis[MXN];

int n,m;
unsigned x,y,z;
unsigned rng61(){
  LL t;
  x ^= x << 16;
  x ^= x >> 5;
  x ^= x << 1;
  t = x;
  x = y;
  y = z;
  z = t ^ x ^ y;
  return z;
}

void qk_sort(int l,int r,int k)
{
    if (l>=r) return;
    int a=l, b=r;
    while (a<b)
    {
        while (a<b&&data[b]>=data[l]) b--;
        while (a<b&&data[a]<=data[l]) a++;
        swap(data[a],data[b]);
    }
    swap(data[l],data[a]);
    vis[a]=1;
    if (k==a) return;
    if (k<a) qk_sort(l,a-1,k);
    if (k>a) qk_sort(a+1,r,k);
}

int main()
{
    int cnt=1;
    while (scanf("%d%d%u%u%u",&n,&m,&x,&y,&z)!=EOF)
    {
        for (int i=0;i<m;i++)
            scanf("%d",&num[i]);
        for (int i=0;i<n;i++)
            data[i]=(LL)rng61();

        memset(vis,0,sizeof(vis));

        for (int i=0;i<m;i++)
        {
            int l =num[i],r=num[i];
            while (l>=0&&vis[l]==0) l--;
            l++;
            while (r<n&&vis[r]==0) r++;
            r--;
            qk_sort(l,r,num[i]);
            prt[i] = data[num[i]];
        }
        printf("Case #%d:",cnt++);
        for (int i=0;i<m;i++)
            printf(" %lld",prt[i]);
        printf("
");
    }
    return 0;
}

STL   里面的   nth_element(arr,arr+x,arr+n);

可以将x在[0,n]范围内，将第x小的数字移动到arr[x]上，其余比arr[x]大的，在x后面，比arr[x]小的，在x前面。

1684 ms 

STL 用得好省事多啊

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;
#define LL long long
#define MXN 10000005
#define MXM 105
struct Node
{
    int w;
    int p;
    bool operator <(const Node b) const
    {
        return w<b.w;
    }
}num[MXM];
LL prt[MXM];
LL data[MXN];
bool vis[MXN];

int n,m;
unsigned x,y,z;
unsigned rng61(){
  LL t;
  x ^= x << 16;
  x ^= x >> 5;
  x ^= x << 1;
  t = x;
  x = y;
  y = z;
  z = t ^ x ^ y;
  return z;
}

int main()
{
    int cnt=1;
    while (scanf("%d%d%u%u%u",&n,&m,&x,&y,&z)!=EOF)
    {
        for (int i=0;i<m;i++)
        {
            scanf("%d",&num[i].w);
            num[i].p=i;
        }
        sort(num,num+m);

        for (int i=0;i<n;i++)
            data[i]=(LL)rng61();

        memset(vis,0,sizeof(vis));

        for (int i=m-1;i>=0;i--)
        {
            if (i==m-1)
                nth_element(data,data+num[i].w,data+n);
            else
                nth_element(data,data+num[i].w,data+num[i+1].w);
            prt[num[i].p] = data[num[i].w];
        }
        printf("Case #%d:",cnt++);
        for (int i=0;i<m;i++)
            printf(" %lld",prt[i]);
        printf("
");
    }
    return 0;
}