HDU 6197 array array array 2017沈阳网络赛 LIS

#include <bits/stdc++.h>
using namespace std;
const int maxn = 100010;
int a[maxn], b[maxn];
int Search(int num, int low, int high)
{
    int mid;
    while(low<=high){
        mid=(low+high)/2;
        if(num>=b[mid]) low=mid+1;
        else high=mid-1;
    }
    return low;
}
int DP(int n){
    int i,len,pos;
    b[1]=a[1];
    len=1;
    for(i=2; i<=n; i++){
        if(a[i]>=b[len]){
            len++;
            b[len]=a[i];
        }
        else{
            pos=Search(a[i], 1, len);
            b[pos] = a[i];
        }
    }
    return len;
}

int main()
{
    int T,n,k;
    scanf("%d", &T);
    while(T--){
        scanf("%d %d", &n,&k);
        for(int i=1; i<=n; i++){
            scanf("%d", &a[i]);
        }
        int len = DP(n);
        int l=1,r=n;
        while(l<=r){
            swap(a[l],a[r]);
            l++;
            r--;
        }
        len = max(len, DP(n));
        if(n-len>k){
            printf("A is not a magic array.\n");
        }
        else{
            printf("A is a magic array.\n");
        }
    }
    return 0;
}