hihocoder#1384/北京网络赛2016 Genius ACM 归并排序+倍增

考虑固定l，每次查找符合的r，每次倍增长度p，用归并排序将后面的可行的部分归并进去，时间复杂度O(nlogn)，不用读入挂就T了

/* ***********************************************
Author        :BPM136
Created Time  :2018/7/15 15:37:13
File Name     :1384.cpp
************************************************ */

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<vector>
using namespace std;

typedef long long ll;

namespace fastIO{  
    #define BUF_SIZE 100000  
    #define OUT_SIZE 100000  
    //fread->read  
    bool IOerror=0;  
    inline char nc(){  
        static char buf[BUF_SIZE],*p1=buf+BUF_SIZE,*pend=buf+BUF_SIZE;  
        if (p1==pend){  
            p1=buf; pend=buf+fread(buf,1,BUF_SIZE,stdin);  
        if (pend==p1){IOerror=1;return -1;}  
        //{printf("IO error!
");system("pause");for (;;);exit(0);}  
    }  
    return *p1++;  
}  
inline bool blank(char ch){return ch==' '||ch=='
'||ch=='
'||ch=='	';}  
inline void read(int &x){  
    bool sign=0; char ch=nc(); x=0;  
    for (;blank(ch);ch=nc());  
    if (IOerror)return;  
    if (ch=='-')sign=1,ch=nc();  
    for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';  
    if (sign)x=-x;  
}  
inline void read(ll &x){  
    bool sign=0; char ch=nc(); x=0;  
    for (;blank(ch);ch=nc());  
    if (IOerror)return;  
    if (ch=='-')sign=1,ch=nc();  
    for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';  
    if (sign)x=-x;  
}  
inline void read(double &x){  
    bool sign=0; char ch=nc(); x=0;  
    for (;blank(ch);ch=nc());  
    if (IOerror)return;  
    if (ch=='-')sign=1,ch=nc();  
    for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';  
    if (ch=='.'){  
        double tmp=1; ch=nc();  
        for (;ch>='0'&&ch<='9';ch=nc())tmp/=10.0,x+=tmp*(ch-'0');  
    }  
    if (sign)x=-x;  
}  
inline void read(char *s){  
    char ch=nc();  
    for (;blank(ch);ch=nc());  
    if (IOerror)return;  
    for (;!blank(ch)&&!IOerror;ch=nc())*s++=ch;  
    *s=0;  
}  
inline void read(char &c){  
    for (c=nc();blank(c);c=nc());  
    if (IOerror){c=-1;return;}  
} 
#undef OUT_SIZE  
#undef BUF_SIZE  
}; using namespace fastIO;

const int N = 500005;

ll sqr(ll x) { return x*x; }

int t[N];
int merge(int a[],int n,int b[],int m) {
    int ret=0;
    int l1=1,l2=1;
    while(l1<=n && l2<=m) {
        if(a[l1]<b[l2]) {
            t[++ret]=a[l1];
            l1++;
        } else {
            t[++ret]=b[l2];
            l2++;
        }
    }
    while(l1<=n) {
        t[++ret]=a[l1];
        l1++;
    }
    while(l2<=m) {
        t[++ret]=b[l2];
        l2++;
    }
    for(int i=1;i<=ret;i++) a[i]=t[i];
    return ret;
}

int n,m;
ll LIM;
int a[N];
int b[N];
int c[N];

bool check(int a[],int l,int r,int L) {
    ll sum=0;
    for(int i=l,j=r;i<=j && (i-l+1)<=L;i++,j--) {
        sum+=sqr((ll)a[i]-a[j]);
        if(sum>LIM) return 0;
    }
    return 1;
}

void ARR_OUT(int arr[],int num) {
    for(int i=1;i<=num;i++) cerr<<arr[i]<<' '; cerr<<endl;
}

int main() {
    int T;
    read(T);
    while(T--) {
        //scanf("%d%d%d",&n,&m,&LIM);
        read(n); read(m); read(LIM);
        for(int i=1;i<=n;i++) read(a[i]);//scanf("%d",&a[i]);
        int ans=0;
        int l=1,r=l,p=1;
        while(l<=n) {
            b[1]=a[l];
            while(p) {
                if(r+p>n) {
                    p>>=1;
                    continue;
                }
                int i,j;
                for(i=r+1,j=1;i<=r+p;i++,j++) c[j]=a[i];
                sort(c+1,c+j);
                int num=merge(c,j-1,b,r-l+1);
                if(check(c,1,num,m)) {
                    for(int i=1;i<=num;i++) b[i]=c[i];
                    r=r+p;
                    p<<=1;
                } else {
                    p>>=1;
                }
            }
            ans++;
            l=r+1; r=l; p=1;
        }
        printf("%d
",ans);
    }
    return 0;
}