hdu 6197 array array array

array array array

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 459    Accepted Submission(s): 282

Problem Description

One day, Kaitou Kiddo had stolen a priceless diamond ring. But detective Conan blocked Kiddo's path to escape from the museum. But Kiddo didn't want to give it back. So, Kiddo asked Conan a question. If Conan could give a right answer, Kiddo would return the ring to the museum.
Kiddo: "I have an array A

and a number k

, if you can choose exactly k

elements from A

and erase them, then the remaining array is in non-increasing order or non-decreasing order, we say A

is a magic array. Now I want you to tell me whether A

is a magic array. " Conan: "emmmmm..." Now, Conan seems to be in trouble, can you help him?

 

Input

The first line contains an integer T indicating the total number of test cases. Each test case starts with two integers n

and k

in one line, then one line with n

integers: A1,A2…An

.
1≤T≤20

1≤n≤105

0≤k≤n

1≤Ai≤105

 

Output

For each test case, please output "A is a magic array." if it is a magic array. Otherwise, output "A is not a magic array." (without quotes).

 

Sample Input

3
4 1
1 4 3 7
5 2
4 1 3 1 2
6 1
1 4 3 5 4 6

 

Sample Output

A is a magic array.
A is a magic array.
A is not a magic array.

 

Source

2017 ACM/ICPC Asia Regional Shenyang Online

 

这道题转换之后就是求最长上升子序列长度，此外，发现了一种二分求LIS方法。

 

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
#include<vector>
#include<cmath>
#include<string>
#define LL long long
const int maxn=1e5+5;
using namespace std;
int a[maxn],b[maxn],c[maxn];
int n;
int LIS(int *d){
    memset(c,0,sizeof(c));
    c[1]=d[1];
    int l,r,mid,len=1;
    for(int i=2;i<=n;i++){
        l=1;
        r=len;
        while(l<=r){
        mid=(l+r)/2;
        if(c[mid]<=d[i]) l=mid+1;
        else  r=mid-1;
        }
        c[l]=d[i];
        if(l>len) len++;

    }
    return len;
}
int main()
{
    int T;
    scanf("%d",&T);
    int k;
    while(T--)
    {
        scanf("%d%d",&n,&k);
        for(int i=1;i<=n;i++)
        {
            scanf("%d",&a[i]);
            b[i]=-a[i];
        }
        int maxn=max(LIS(a),LIS(b));

        if(n-maxn>k)
        printf("A is not a magic array.\n");
        else
        printf("A is a magic array.\n");
    }
    return 0;
}