标签:fread pen def img size alt 复杂度 || math
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
1 /* *********************************************** 2 Author :BPM136 3 Created Time :2018/7/15 15:37:13 4 File Name :1384.cpp 5 ************************************************ */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<algorithm> 10 #include<cstdlib> 11 #include<cmath> 12 #include<cstring> 13 #include<vector> 14 using namespace std; 15 16 typedef long long ll; 17 18 namespace fastIO{ 19 #define BUF_SIZE 100000 20 #define OUT_SIZE 100000 21 //fread->read 22 bool IOerror=0; 23 inline char nc(){ 24 static char buf[BUF_SIZE],*p1=buf+BUF_SIZE,*pend=buf+BUF_SIZE; 25 if (p1==pend){ 26 p1=buf; pend=buf+fread(buf,1,BUF_SIZE,stdin); 27 if (pend==p1){IOerror=1;return -1;} 28 //{printf("IO error!\n");system("pause");for (;;);exit(0);} 29 } 30 return *p1++; 31 } 32 inline bool blank(char ch){return ch==‘ ‘||ch==‘\n‘||ch==‘\r‘||ch==‘\t‘;} 33 inline void read(int &x){ 34 bool sign=0; char ch=nc(); x=0; 35 for (;blank(ch);ch=nc()); 36 if (IOerror)return; 37 if (ch==‘-‘)sign=1,ch=nc(); 38 for (;ch>=‘0‘&&ch<=‘9‘;ch=nc())x=x*10+ch-‘0‘; 39 if (sign)x=-x; 40 } 41 inline void read(ll &x){ 42 bool sign=0; char ch=nc(); x=0; 43 for (;blank(ch);ch=nc()); 44 if (IOerror)return; 45 if (ch==‘-‘)sign=1,ch=nc(); 46 for (;ch>=‘0‘&&ch<=‘9‘;ch=nc())x=x*10+ch-‘0‘; 47 if (sign)x=-x; 48 } 49 inline void read(double &x){ 50 bool sign=0; char ch=nc(); x=0; 51 for (;blank(ch);ch=nc()); 52 if (IOerror)return; 53 if (ch==‘-‘)sign=1,ch=nc(); 54 for (;ch>=‘0‘&&ch<=‘9‘;ch=nc())x=x*10+ch-‘0‘; 55 if (ch==‘.‘){ 56 double tmp=1; ch=nc(); 57 for (;ch>=‘0‘&&ch<=‘9‘;ch=nc())tmp/=10.0,x+=tmp*(ch-‘0‘); 58 } 59 if (sign)x=-x; 60 } 61 inline void read(char *s){ 62 char ch=nc(); 63 for (;blank(ch);ch=nc()); 64 if (IOerror)return; 65 for (;!blank(ch)&&!IOerror;ch=nc())*s++=ch; 66 *s=0; 67 } 68 inline void read(char &c){ 69 for (c=nc();blank(c);c=nc()); 70 if (IOerror){c=-1;return;} 71 } 72 #undef OUT_SIZE 73 #undef BUF_SIZE 74 }; using namespace fastIO; 75 76 const int N = 500005; 77 78 ll sqr(ll x) { return x*x; } 79 80 int t[N]; 81 int merge(int a[],int n,int b[],int m) { 82 int ret=0; 83 int l1=1,l2=1; 84 while(l1<=n && l2<=m) { 85 if(a[l1]<b[l2]) { 86 t[++ret]=a[l1]; 87 l1++; 88 } else { 89 t[++ret]=b[l2]; 90 l2++; 91 } 92 } 93 while(l1<=n) { 94 t[++ret]=a[l1]; 95 l1++; 96 } 97 while(l2<=m) { 98 t[++ret]=b[l2]; 99 l2++; 100 } 101 for(int i=1;i<=ret;i++) a[i]=t[i]; 102 return ret; 103 } 104 105 int n,m; 106 ll LIM; 107 int a[N]; 108 int b[N]; 109 int c[N]; 110 111 bool check(int a[],int l,int r,int L) { 112 ll sum=0; 113 for(int i=l,j=r;i<=j && (i-l+1)<=L;i++,j--) { 114 sum+=sqr((ll)a[i]-a[j]); 115 if(sum>LIM) return 0; 116 } 117 return 1; 118 } 119 120 void ARR_OUT(int arr[],int num) { 121 for(int i=1;i<=num;i++) cerr<<arr[i]<<‘ ‘; cerr<<endl; 122 } 123 124 int main() { 125 int T; 126 read(T); 127 while(T--) { 128 //scanf("%d%d%d",&n,&m,&LIM); 129 read(n); read(m); read(LIM); 130 for(int i=1;i<=n;i++) read(a[i]);//scanf("%d",&a[i]); 131 int ans=0; 132 int l=1,r=l,p=1; 133 while(l<=n) { 134 b[1]=a[l]; 135 while(p) { 136 if(r+p>n) { 137 p>>=1; 138 continue; 139 } 140 int i,j; 141 for(i=r+1,j=1;i<=r+p;i++,j++) c[j]=a[i]; 142 sort(c+1,c+j); 143 int num=merge(c,j-1,b,r-l+1); 144 if(check(c,1,num,m)) { 145 for(int i=1;i<=num;i++) b[i]=c[i]; 146 r=r+p; 147 p<<=1; 148 } else { 149 p>>=1; 150 } 151 } 152 ans++; 153 l=r+1; r=l; p=1; 154 } 155 printf("%d\n",ans); 156 } 157 return 0; 158 }
hihocoder#1384/北京网络赛2016 Genius ACM 归并排序+倍增
标签:fread pen def img size alt 复杂度 || math
原文地址:https://www.cnblogs.com/MyGirlfriends/p/9314072.html